Use of anti-fam19a5 antibodies for treating fibrosis

ABSTRACT

The present disclosure relates to the pharmaceutical use of antagonists (e.g., an antibody or antigen-binding portion thereof) that specifically bind to FAM19A5 to treat or to diagnose a fibrosis and/or a fibrosis-associated disease in a subject in need thereof.

The content of the electronically submitted sequence listing in ASCII text file (Name: 3763.004PC02_SeqListing.ST25.txt; Size: 166,853 bytes; and Date of Creation: Jun. 26, 2018) filed with the application is incorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure provides methods for the treatment or diagnosis of fibrosis in a subject (e.g., a human) using antibodies that specifically bind to family with sequence similarity 19, member A5 (FAM19A5), or an antigen binding fragment thereof, or a composition comprising such antibodies or antigen binding fragment thereof.

BACKGROUND OF THE DISCLOSURE

Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in response to certain injuries. Generally, acute wounds normally heal in an orderly and efficient manner through a process that is characterized by four distinct phases: hemostasis, inflammation, proliferation, and remodeling. Diegelmann R. F. et al., Front Biosci 9:283-289 (2004). However, where the injury is severe or repetitive, dysregulation of the wound healing process can occur, which is marked by excessive accumulation of fibrous connective tissues in and around the damaged tissue. Wynn T. A. et al., Nat Med 18(7):1028-1040 (2012). Such accumulation can lead to permanent scarring, organ malfunction, and even death, as observed in many fibrotic diseases (e.g., chronic liver disease, kidney disease, idiopathic pulmonary fibrosis (IPF), and heart failure).

Liver (or hepatic) fibrosis is the excessive accumulation of scar tissues that results from ongoing inflammation and hepatic cell death that occurs in most types of chronic liver diseases. The main causes of liver fibrosis, at least in industrialized countries, include chronic hepatitis virus infection, alcohol abuse, iron and copper overload, and nonalcoholic steatohepatitis (NASH). Bataller R et al., J Clin Invest 115(2): 209-218 (2005). Upon repeated damage to the liver, the hepatocytes produce reactive oxygen species (ROS) and other inflammatory mediators (e.g., cytokines such as TGF-β, PDGF, TNF-α, IL-1 and GM-CSF), which help activate different hepatic cells (e.g., hepatic stellate cells (HSCs), myofibroblasts, interstitial fibroblasts, and bile duct epithelial cells).

The activated hepatic cells undergo series of morphological and functional changes (e.g., appearance of the cytoskeletal protein smooth muscle α-actin (α-SMA), a loss in the cellular vitamin A stores, an increase in the appearance of rough endoplasmic reticulum, and increased collagen mRNA expression). Tsukada et al., Clin Chim Acta 364(1-2): 33-60 (2006). These activated cells migrate to the site of the damage, where they produce a large amount of ECM (largely composed of collagen, glycoprotein, and proteoglycan), which accumulate and distort the hepatic architecture by forming fibrous scars.

Generally, hepatic fibrosis can be reversed if the source of the damage is removed. However, with repeated damage, increased cross-linking between the ECMs can occur, leading to the formation of thick fibrils and the progression to cirrhosis.

Currently, there are no standard treatment for many fibrotic diseases, particularly liver fibrosis. And even those with approved treatment options available (e.g., idiopathic pulmonary fibrosis), the removal of the causative agent is still the most effective treatment available. Moreover, the most reliable method currently available for diagnosing fibrosis (e.g., liver fibrosis) is through tissue biopsy. But such method is often highly invasive and has various undesirable side effects (e.g., hemorrhage at site of biopsy, pain and discomfort). Accordingly, there is a current need for more effective treatment and diagnostic options for fibrosis in a subject (e.g., a human).

BRIEF SUMMARY OF THE DISCLOSURE

Provided herein is an antagonist against a family with sequence similarity 19, member A5 (FAM19A5) protein (“FAM19A5 antagonist”) for treating a fibrosis of a tissue in a subject in need thereof.

In some embodiments, the fibrosis is selected from the group consisting of a hepatic fibrosis, pulmonary fibrosis, renal fibrosis, myelofibrosis, pancreatic fibrosis, skin fibrosis, cardiac fibrosis, arterial fibrosis, arthrofibrosis, breast fibrosis, muscle fibrosis, retroperitoneal Fibrosis, thyroid fibrosis, lymph node fibrosis, bladder fibrosis, systemic fibrosis, and pleural fibrosis.

In some embodiments, the FAM19A5 antagonist decreases accumulation of an extracellular matrix protein (e.g., collagen) within the tissue.

In some embodiments, the FAM19A5 antagonist is an antibody, or an antigen-binding portion thereof, that specifically binds to the FAM19A5 protein (“anti-FAM19A5 antibody”). In some embodiments, the anti-FAM19A5 antibody is a chimeric antibody, a humanized antibody, or a human antibody.

In some embodiments, the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 11, 12, and 13, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 23, 24, and 25, respectively. In other embodiments, the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 14, 15, and 16, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 26, 27, and 28, respectively. In further embodiments, the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 17, 18, and 19, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 29, 30, and 31, respectively. In certain embodiments, the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 20, 21, and 22, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 32, 33, and 34, respectively.

Also provided herein is a method of in vitro diagnosing a fibrosis or a fibrosis-associated disease comprising contacting an FAM19A5 antagonist with a biological sample of the subject and measuring a FAM19A5 protein level or a FAM19A5 mRNA level in the sample. In some embodiments, the FAM19A5 antagonist is an anti-FAM19A5 antibody.

In some embodiments, the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 11, 12, and 13, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 23, 24, and 25, respectively. In certain embodiments, the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 14, 15, and 16, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 26, 27, and 28, respectively. In other embodiments, the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 17, 18, and 19, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 29, 30, and 31, respectively. In further embodiments, the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 20, 21, and 22, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 32, 33, and 34, respectively.

EMBODIMENTS Embodiment 1

A method for treating a fibrosis in a subject in need thereof comprising administering to the subject an antagonist against a family with sequence similarity 19, member A5 (FAM19A5) protein.

Embodiment 2

The method of Embodiment 1, wherein the fibrosis is selected from the group consisting of a hepatic fibrosis, pulmonary fibrosis, renal fibrosis, myelofibrosis, pancreatic fibrosis, skin fibrosis, cardiac fibrosis, arterial fibrosis, arthrofibrosis, breast fibrosis, muscle fibrosis, retroperitoneal Fibrosis, thyroid fibrosis, lymph node fibrosis, bladder fibrosis, systemic fibrosis, and pleural fibrosis.

Embodiment 3

The method of Embodiment 1 or 2, wherein the fibrosis is associated with or caused by scleroderma, connective tissue diseases, alcoholism, an infection, iron deposition, environmental pollutants, radiation therapy, chemotherapy, heart medications, anti-inflammatory drugs, dermatomyositis, polymyositis, systemic lupus erythematosus, osteoarthritis, rheumatoid arthritis, sarcoidosis, non-alcoholic steatohepatitis, or any combination thereof.

Embodiment 4

The method of Embodiment 2, wherein the fibrosis is hepatic fibrosis or pulmonary fibrosis.

Embodiment 5

The method of Embodiment 4, wherein the hepatic fibrosis is associated with irreversible cirrhosis.

Embodiment 9

The method of any one of Embodiments 1 to 8, wherein the antagonist is an antisense oligonucleotide, siRNA, shRNA, miRNA, dsRNA, aptamer, PNA targeting FAM19A5, or a vector including the same.

Embodiment 10

The method of any one of Embodiments 1 to 8, wherein the antagonist is an antibody, or an antigen-binding portion thereof, that specifically binds to the FAM19A5 protein (“an anti-FAM19A5 antibody or antigen-binding portion thereof”), a polynucleotide encoding the anti-FAM19A5 antibody or antigen-binding portion thereof, or a vector comprising the polynucleotide thereof.

Embodiment 11

A method of diagnosing a fibrosis and/or a fibrosis-associated disease in a subject in need thereof comprising contacting an anti-FAM19A5 antibody or antigen-binding portion thereof with a biological sample of the subject and measuring a protein level of FAM19A5 or an mRNA level encoding FAM19A5 protein in the sample.

Embodiment 12

A method of measuring a protein level of FAM19A5 or an mRNA level encoding FAM19A5 protein in a subject having a fibrosis comprising contacting an anti-FAM19A5 antibody or antigen-binding portion thereof with a biological sample of the subject.

Embodiment 13

The method of Embodiment 11 or 12, wherein the subject exhibits at least 1.5 fold, at least 2 fold, at least 3 fold, at least 4 fold, at least 5 fold, at least 6 fold, at least 7 fold, at least 8 fold, at least 9 fold, at least 10 fold, at least 11 fold, at least 12 fold, at least 13 fold, at least 15 fold, at least 20 fold, at least 25 fold, or at least 30 fold increase in the protein level of FAM19A5 or an mRNA level encoding FAM19A5 protein compared to the protein level of FAM19A5 or an mRNA level encoding FAM19A5 protein in a reference sample (sample of a subject who does not have a fibrosis).

Embodiment 14

The method of any one of Embodiments 11 to 13, further comprising collecting the biological sample from the subject prior to the measuring.

Embodiment 15

The method of any one of Embodiments 11 to 14, wherein the protein level of FAM19A5 is measured by an immunohistochemistry, a Western blotting, a radioimmunoassay, an enzyme linked immunosorbent assay (ELISA), a radioimmunodiffusion, an immunoprecipitation assay, an Ouchterlony immunodiffusion method, a rocket immunoelectrophoresis, a tissue immunostaining method, a complement fixation assay, FACS, or a protein chip.

Embodiment 16

The method of any one of Embodiments 11 to 14, wherein the mRNA level encoding FAM19A5 is measured by a RT-PCT, a real time polymerase chain reaction, or a Northern blot.

Embodiment 17

The method of any one of Embodiments 11 to 16, wherein the biological sample comprises a tissue, cell, blood, serum, plasma, saliva, cerebro spinal fluid, intravitreal fluid, or urine.

Embodiment 18

The method of any one of Embodiments 10 to 17, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof exhibits a property selected from:

(a) binds to soluble human FAM19A5 with a KD of 10 nM or less as measured by enzyme-linked immunosorbent assay (ELISA); (b) binds to membrane bound human FAM19A5 with a KD of 10 nM or less as measured by ELISA; and (c) both (a) and (b).

Embodiment 19

The method of any one of Embodiments 10 to 18 wherein the anti-FAM19A5 antibody or antigen-binding portion thereof cross-competes for binding to a human FAM19A5 epitope with a reference antibody comprising heavy chain CDR1, CDR2, and CDR3 and light chain CDR1, CDR2, and CDR3,

(i) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 11, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 12, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 13, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 23, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 24, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 25; (ii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 14, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 15, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 16, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 26, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 27, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 28; (iii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 17, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 18, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 19, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 29, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 30, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 31; or (iv) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 20, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 21, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 22, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 32, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 33, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 34.

Embodiment 20

The method of any one of Embodiments 10 to 19, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof binds to the same FAM19A5 epitope as a reference antibody comprising heavy chain CDR1, CDR2, and CDR3 and light chain CDR1, CDR2, and CDR3,

(i) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 11, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 12, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 13, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 23, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 24, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 25; (ii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 14, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 15, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 16, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 26, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 27, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 28; (iii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 17, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 18, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 19, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 29, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 30, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 31; or (iv) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 20, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 21, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 22, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 32, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 33, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 34.

Embodiment 21

The method of any one of Embodiments 10 to 20, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof binds to at least one FAM19A5 epitope, which is SEQ ID NO: 6 or SEQ ID NO: 9.

Embodiment 22

The method of any one of Embodiments 10 to 20, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof binds only to an FAM19A5 epitope, which is SEQ ID NO: 6 or SEQ ID NO: 9.

Embodiment 23

The method of any one of Embodiments 10 to 21, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof further binds to an additional FAM19A5 epitope.

Embodiment 24

The method of Embodiment 23, wherein the additional FAM19A5 epitope is selected from the group consisting of SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, and any combination thereof.

Embodiment 25

The method of any one of Embodiments 10 to 24, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof comprises a heavy chain CDR1, CDR2, and CDR3 and a light chain CDR1, CDR2, and CDR3.

Embodiment 26

The method of Embodiment 25, wherein the heavy chain CDR3 of the anti-FAM19A5 antibody or antigen-binding portion thereof comprises the amino acid sequence of SEQ ID NO: 13, SEQ ID NO: 16, SEQ ID NO: 19, or SEQ ID NO: 22.

Embodiment 27

The method of Embodiment 25 or 26, wherein the heavy chain CDR1 of the anti-FAM19A5 antibody or antigen-binding portion thereof comprises the amino acid sequence of SEQ ID NO: 11, SEQ ID NO: 14, SEQ ID NO: 17, or SEQ ID NO: 20.

Embodiment 28

The method of any one of Embodiments 25 to 27, wherein the heavy chain CDR2 of the anti-FAM19A5 antibody or antigen-binding portion thereof comprises the amino acid sequence of SEQ ID NO: 12, SEQ ID NO: 15, SEQ ID NO: 18, or SEQ ID NO: 21.

Embodiment 29

The method of any one of Embodiments 25 to 28, wherein the light chain CDR1 of the anti-FAM19A5 antibody or antigen-binding portion thereof comprises the amino acid sequence of SEQ ID NO: 23, SEQ ID NO: 26, SEQ ID NO: 29, or SEQ ID NO: 32.

Embodiment 30

The method of any one of Embodiments 25 to 29, wherein the light chain CDR2 of the anti-FAM19A5 antibody or antigen binding portion thereof comprises the amino acid sequence of SEQ ID NO: 24, SEQ ID NO: 27, SEQ ID NO: 30, or SEQ ID NO: 33.

Embodiment 31

The method of any one of Embodiments 25 to 30, wherein the light chain CDR3 of the anti-FAM19A5 antibody or antigen binding portion thereof comprises the amino acid sequence of SEQ ID NO: 25, SEQ ID NO: 28, SEQ ID NO: 31, or SEQ ID NO: 34.

Embodiment 32

The method of any one of Embodiments 10 to 31, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein

(i) the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 11, 12, and 13, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 23, 24, and 25, respectively; (ii) the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 14, 15, and 16, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 26, 27, and 28, respectively; (iii) the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 17, 18, and 19, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 29, 30, and 31, respectively; or (iv) the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 20, 21, and 22, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 32, 33, and 34, respectively.

Embodiment 33

The method of any one of Embodiments 10 to 32, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof comprises a heavy chain variable domain comprising SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, or SEQ ID NO: 38 and/or a light chain variable domain comprising SEQ ID NO: 39, SEQ ID NO: 40, SEQ ID NO: 41, or SEQ ID NO: 42.

Embodiment 34

The method of Embodiment 33, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof comprises a heavy chain variable domain comprising SEQ ID NO: 35 and a light chain variable domain comprising SEQ ID NO: 39.

Embodiment 35

The method of Embodiment 33, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof comprises a heavy chain variable domain comprising SEQ ID NO: 36 and a light chain variable domain comprising SEQ ID NO: 40.

Embodiment 36

The method of Embodiment 33, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof comprises a heavy chain variable domain comprising SEQ ID NO: 37 and a light chain variable domain comprising SEQ ID NO: 41.

Embodiment 37

The method of Embodiment 33, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof comprises a heavy chain variable domain comprising SEQ ID NO: 38 and a light chain variable domain comprising SEQ ID NO: 42.

Embodiment 38

The method of any one of Embodiments 10 to 32, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof comprises a heavy chain variable region and a light chain variable region, wherein the heavy chain variable region comprises an amino acid sequence which is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to the amino acid sequence set forth as SEQ ID NO: 35, 36, 37, or 38.

Embodiment 39

The method of any one of Embodiments 10 to 32, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof comprises a heavy chain variable region and a light chain variable region, wherein the light chain variable region comprises an amino acid sequence which is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to the amino acid sequence set forth as SEQ ID NO: 39, 40, 41, or 42.

Embodiment 40

The method of any one of Embodiments 10 to 32, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof comprises a heavy chain variable region and a light chain variable region, wherein the light chain variable region comprises an amino acid sequence which is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to the amino acid sequence set forth as SEQ ID NO: 35, 36, 37, or 38; and wherein the light chain variable region comprises an amino acid sequence which is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to the amino acid sequence set forth as SEQ ID NO: 39, 40, 41, or 42.

Embodiment 41

The method of any one of Embodiments 10 to 40, wherein the anti-FAM19A5 antibody is a chimeric antibody, a human antibody, or a humanized antibody.

Embodiment 42

The method of any one of Embodiments 10 to 40, wherein the antigen-binding portion thereof is an Fab, an Fab′, an F(ab′)2, an Fv, or a single chain Fv (scFv).

Embodiment 43

The method of any one of Embodiments 10 to 42, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof is selected from the group consisting of an IgG1, an IgG2, an IgG3, an IgG4, or a variant thereof.

Embodiment 44

The method of Embodiment 43, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof is an IgG2, an IgG4, or a combination thereof.

Embodiment 45

The method of Embodiment 43, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof comprises an IgG2/IgG4 isotype antibody.

Embodiment 46

The method of any one of Embodiments 10 to 45, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof further comprising a constant region without the Fc function.

Embodiment 47

The method of any one of Embodiments 10 to 46, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof is linked to a molecule having a second binding moiety, thereby forming a bispecific molecule.

Embodiment 48

The method of any of Embodiments 10 to 47, wherein the anti-FAM19A5 antibody or antigen-binding portion thereof is linked to an agent, thereby forming an immunoconjugate.

Embodiment 49

The method of any one of Embodiments 1 to 48, wherein the antagonist of the FAM19A5 protein is formulated with a pharmaceutically acceptable carrier.

Embodiment 50

The method of any one of Embodiments 1 to 49, wherein the antagonist of the FAM19A5 protein is administered intravenously, orally, parenterally, intrathecally, intra-cerebroventricularly, pulmonarily, intramuscularly, subcutaneously, intravitreally, or intraventricularly.

Embodiment 51

The method of any one of Embodiments 1 to 50, wherein the subject is a human.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the comparison of the level of FAM19A5 protein in the serum of rats (n=5) with liver fibrosis induced by bile duct ligation (BDL) (“disease model”) against healthy rats (“normal”) (n=3). The level of FAM19A5 protein is shown as fold change over the level observed in normal control animals. “*” indicates a statistically significant difference (p<0.005) compared to the normal control animals.

FIG. 2 shows the comparison of the level of FAM19A5 protein in the serum of rats (n=5) with idiopathic pulmonary fibrosis induced by intratracheal injection of 3 mg/kg bleomycin (“disease model”) against healthy rats (“normal”) (n=5). The level of FAM19A5 protein is shown as fold change over the level observed in normal control animals. “*” indicates a statistically significant difference (p<0.005) compared to the normal control animals.

FIG. 3 shows the fold change in the level of FAM19A5 protein in the serum of both human patients with confirmed liver fibrosis, e.g., cirrhosis, (patient #1-10) and healthy individuals (normal #1-3). The specific value shown above each bar graph denotes the fold change over the average concentration of the FAM19A5 protein detected in the serum of the healthy individuals.

FIG. 4 shows a comparison of an H&E (hematoxylin and eosin) staining of the left ventricular tissue in myocardial infarction-induced animals treated with a control antibody (“NHI”) or an anti-FAM19A5 antibody (“1-65,” “3-2,” and “1-28”). Healthy animals (i.e., no myocardial infarction induction, “naïve”) were used as additional control.

FIGS. 5A and 5B show a comparison of collagen accumulation in the left ventricular tissue of myocardial infarction-induced animals. The myocardial infarction-induced animals received either a control antibody (“NHI”) or an anti-FAM19A5 antibody (“1-65,” “3-2,” and “1-28”). Healthy animals (i.e., no myocardial infarction induction, “naïve”) were again used as additional control. FIG. 5A shows the collagen accumulation using the Masson's trichrome staining. FIG. 5B shows the collagen accumulation (i.e., fibrous area) as a ratio of fibrous area to the entire left ventricular area. Data are expressed as mean±S.D. (n=5 to 8 per group). “***/**” above the bars indicates a statistically significant difference (p<0.001, p<0.05, respectively) compared to the “Naïve” group (healthy animals). “#” above the bars indicate a statistically significant difference (p<0.05) compared to the “NHI” group (myocardial infarction induction+control antibody).

FIG. 6A provides the administration schedule for assessing the anti-fibrotic effect of anti-FAM19A5 antibody in a dimethylnitrosamine (DMN)-mediated fibrosis animal model. The dark gray box indicates when DMN was administered to the animals to induce liver fibrosis. The light gray box indicates when the control (human IgG) antibody or the anti-FAM19A5 antibody were administered.

FIGS. 6B, 6C, 6D, and 6E show a comparison of collagen production in the liver of DMN-treated animals that received either the control antibody (“G2,” human IgG) or the anti-FAM19A5 antibody (“G3”). A representative naïve/healthy animal (“G1”) is also shown for comparison purpose. In FIGS. 6B and 6C, collagen production is represented by Sirius Red staining (stains total collagen). FIG. 6B provides a representative immunohistochemical image of Sirius Red staining in the liver of DMN-treated animals that received either the control antibody (G2) or the anti-FAM19A5 antibody (G3). FIG. 6C provides the percentage (mean±S.D.) of Sirius Red-positive cells relative to the liver tissue section. In FIGS. 6D and 6E, the specific production of type I collagen is provided. FIG. 6D provides a representative immunohistochemical image of type I collagen staining in the liver of DMN-treated animals that received either the control antibody (G2) or the anti-FAM19A5 antibody (G3). FIG. 6E provides the percentage (mean±S.D.) of type I collagen expression relative to the entire stained liver tissue section. In both FIGS. 6C and 6E, statistical analysis was done using SPSS statistics 19. “**” above the bars indicates a statistically significant difference (p<0.01) compared to the “G1” group (healthy animals). “#” and “##” indicate a statistically significant difference (p<0.05; p<0.01, respectively) compared to animals treated with the control antibody (G2).

FIGS. 7A and 7B show a comparison of TGF-β production in the liver of DMN-treated animals that received either the control antibody (G2) or the anti-FAM19A5 antibody (G3). Naïve/healthy animal (G1) is also shown for comparison purpose. FIG. 7A provides a representative immunohistochemical image of TGF-β staining in the liver samples. FIG. 7B provides the percentage (mean±S.D.) of TGF-β expression relative to the liver tissue section. Statistical analysis was done using SPSS statistics 19. “*” and “**” above the bars indicate a statistically significant difference (p<0.05; p<0.01, respectively) compared to “G1” (healthy animals). “##” indicates a statistically significant difference (p<0.01) compared to animals treated with the control antibody (G2).

DETAILED DESCRIPTION OF THE DISCLOSURE

The present disclosure shows that fibrosis, e.g., liver fibrosis, can be controlled, treated, ameliorated, or reduced by administration of an anti-FAM19A5 antagonist, e.g., an anti-FAM19A5 antibody. Not being bound by any theory, one possible mechanism of the efficacy can be due to the anti-inflammatory effect of anti-FAM19A5 antibodies on fibrosis. The disclosure also indicates that fibrosis, e.g., liver fibrosis, can be diagnosed by measuring the expression of FAM19A5 in serum. During fibrosis formation, activated hepatic stellate cells (HSCs), the major culprit in many fibrosis, produce high levels of FAM19A5 protein, which can be secreted into the serum. Accordingly, with increased severity of the fibrosis and/or fibrosis-associated disease, there is a higher FAM19A5 protein expression in the serum.

To facilitate an understanding of the disclosure disclosed herein, a number of terms and phrases are defined. Additional definitions are set forth throughout the detailed description.

I. Definitions

Throughout this disclosure, the term “a” or “an” entity refers to one or more of that entity; for example, “an antibody,” is understood to represent one or more antibodies. As such, the terms “a” (or “an”), “one or more,” and “at least one” can be used interchangeably herein.

Furthermore, “and/or” where used herein is to be taken as specific disclosure of each of the two specified features or components with or without the other. Thus, the term “and/or” as used in a phrase such as “A and/or B” herein is intended to include “A and B,” “A or B,” “A” (alone), and “B” (alone). Likewise, the term “and/or” as used in a phrase such as “A, B, and/or C” is intended to encompass each of the following aspects: A, B, and C; A, B, or C; A or C; A or B; B or C; A and C; A and B; B and C; A (alone); B (alone); and C (alone).

It is understood that wherever aspects are described herein with the language “comprising,” otherwise analogous aspects described in terms of “consisting of” and/or “consisting essentially of” are also provided.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure is related. For example, the Concise Dictionary of Biomedicine and Molecular Biology, Juo, Pei-Show, 2nd ed., 2002, CRC Press; The Dictionary of Cell and Molecular Biology, 3rd ed., 1999, Academic Press; and the Oxford Dictionary Of Biochemistry And Molecular Biology, Revised, 2000, Oxford University Press, provide one of skill with a general dictionary of many of the terms used in this disclosure.

Units, prefixes, and symbols are denoted in their Systeme International de Unites (SI) accepted form. Numeric ranges are inclusive of the numbers defining the range. Unless otherwise indicated, amino acid sequences are written left to right in amino to carboxy orientation. The headings provided herein are not limitations of the various aspects of the disclosure, which can be had by reference to the specification as a whole. Accordingly, the terms defined immediately below are more fully defined by reference to the specification in its entirety.

The term “about” is used herein to mean approximately, roughly, around, or in the regions of. When the term “about” is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical values set forth. In general, the term “about” can modify a numerical value above and below the stated value by a variance of, e.g., 10 percent, up or down (higher or lower).

The terms “treat,” “treating,” and “treatment,” as used herein, refer to any type of intervention or process performed on, or administering an active agent to, the subject with the objective of reversing, alleviating, ameliorating, inhibiting, or slowing down or preventing the progression, development, severity or recurrence of a symptom, complication, condition or biochemical indicia associated with a disease. Treatment can be of a subject having a disease or a subject who does not have a disease (e.g., for prophylaxis).

As used herein, “administering” refers to the physical introduction of a therapeutic agent or a composition comprising a therapeutic agent to a subject, using any of the various methods and delivery systems known to those skilled in the art. The different routes of administration for antibodies described herein include intravenous, intraperitoneal, intramuscular, subcutaneous, spinal or other parenteral routes of administration, for example by injection or infusion. The phrase “parenteral administration” as used herein means modes of administration other than enteral and topical administration, usually by injection, and includes, without limitation, intravenous, intraperitoneal, intramuscular, intraarterial, intrathecal, intralymphatic, intralesional, intracapsular, intraorbital, intracardiac, intradermal, transtracheal, intratracheal, pulmonary, subcutaneous, subcuticular, intraarticular, subcapsular, subarachnoid, intraventricle, intravitreal, epidural, and intrasternal injection and infusion, as well as in vivo electroporation. Alternatively, an antibody described herein can be administered via a non-parenteral route, such as a topical, epidermal or mucosal route of administration, for example, intranasally, orally, vaginally, rectally, sublingually or topically. Administering can also be performed, for example, once, a plurality of times, and/or over one or more extended periods.

The term “therapeutically effective amount” as used herein refers to an amount of a drug, alone or in combination with another therapeutic agent, effective to “treat” a disease or disorder in a subject or reduce the risk, potential, possibility or occurrence of a disease or disorder (e.g., a hepatic fibrosis or a pulmonary fibrosis). A “therapeutically effective amount” includes an amount of a drug or a therapeutic agent that provides some improvement or benefit to a subject having or at risk of having a disease or disorder (e.g., a hepatic fibrosis or a pulmonary fibrosis disclosed herein). Thus, a “therapeutically effective” amount is an amount that reduces the risk, potential, possibility or occurrence of a disease or provides disorder or some alleviation, mitigation, and/or reduces at least one indicator (e.g., fibrosis), and/or decrease in at least one clinical symptom of a disease or disorder.

Some aspect of the present disclosure relates to the diagnosis of fibrosis, and/or a fibrosis-associated disease in a subject in need thereof. In connection with the current disclosure, Applicant has found that upon damage to a tissue or an organ there is an increase in FAM19A5 expression both at the site of damage and in the peripheral blood of a subject with a fibrotic disease or disorder. Accordingly, in some embodiments, the present disclosure provides a method of diagnosing a fibrosis and/or a fibrosis-associated disease in a subject in need thereof comprising contacting the monoclonal antibody or antigen-binding portion thereof, the bispecific molecule, or the immunoconjugate, disclosed herein, with a sample obtained from the subject and measuring the FAM19A5 expression level. In one embodiment, the fibrosis is a liver fibrosis or a pulmonary fibrosis. In some embodiments, the level of FAM19A5 is increased in the sample of the subject as compared to the level of FAM19A5 in a reference sample of a subject without the fibrosis. See infra.

The term “diagnosis” as used herein refers to methods that can be used to determine or predict whether a patient is suffering from a given disease or condition. A skilled artisan can make a diagnosis on the basis of one or more diagnostic marker (e.g., FAM19A5), where the presence, absence, amount, or change in amount of the diagnostic marker is indicative of the presence, severity, or absence of the condition. In some embodiments, an increase in FAM19A5 expression, in a biological sample from a subject, is indicative of fibrosis and/or fibrosis-associated disease. The term “diagnosis” does not refer to the ability to determine the presence or absence of a particular disease with 100% accuracy, or even that a given course or outcome is more likely to occur than not. Instead, the skilled artisan will understand that the term “diagnosis” refers to an increased probability that a certain disease is present in the subject.

The term “diagnostic marker” (e.g., FAM19A5 expression) refers to a material capable of separately diagnosing cells of fibrotic tissues from normal cells, and includes organic bio-molecules such as polypeptides, or nucleic acids (for example, mRNA), lipids, glycolipids, glycoproteins, and sugars (monosaccharides, disaccharides, oligosaccharides, and the like) which increase or decrease in cells of fibrotic tissues. The diagnostic marker provided in the present disclosure for fibrosis and/or fibrosis-associated disease can be a protein that is expressed from FAM19A5 genes of which the expression increases in cells of fibrotic tissues.

The composition for diagnosing fibrosis and/or fibrosis-associated disease includes an agent for measuring the expression level of mRNA of FAM19A5 genes or the amount of protein expressed. Such agents include oligonucleotides having a sequence complementary to FAM19A5 mRNA, a primer or a nucleic acid probe that specifically binds to FAM19A5 mRNA, and antibodies that specifically bind to the FAM19A5 protein.

As used herein, the term “subject” includes any human or non-human animal. The term “non-human animal” includes all vertebrates, e.g., mammals and non-mammals, such as non-human primates, sheep, dog, cow, chickens, amphibians, reptiles, etc.

The term “family with sequence similarity 19, member A5” or “FAM19A5” refers to a protein that belongs to the TAFA family (also known as FAM19 family) of five highly homologous proteins and is predominantly expressed in brain and the spinal cord. Tang T. Y. et al., Genomics 83(4):727-34 (2004). These proteins contain conserved cysteine residues at fixed positions, and are distantly related to macrophage inflammatory protein 1-alpha (MIP-1-alpha), a member of the CC-chemokine family. The TAFA proteins are predominantly expressed in specific regions of the brain and the spinal cord. These proteins are believed to be generated and secreted by adult neural stem cells in neurogenesis processes. FAM19A5 is also known as TAFA5 or Chemokine-like protein TAFA-5.

FAM19A5 is predominantly expressed in the brain of vertebrates and it is believed that FAM19A5 is important in for the development, differentiation, formation of a complete central nervous system. FAM19A5 also plays a significant role in the pathogenesis of many central nervous system damage and/or degenerative brain diseases (e.g., Huntington's disease, Parkinson's disease, Alzheimer's disease, and cerebrospinal damage). Upon damage to the central nervous system, neural stem cells produce FAM19A5, which induces the differentiation of normal astrocytes into reactive astrocytes. These reactive astrocytes (along with microglia) can express a wide array of ECMs (e.g., proteoglycans, glycoproteins, and collagen) and induce reactive gliosis, which can surround the damaged region of the central nervous system like a net and prevent the regeneration of the neurons. Antibodies against FAM19A5 can be used in the prevention and/or treatment of central nervous system injuries and/or diseases. See U.S. Pat. No. 9,579,398.

In humans, the gene encoding FAM19A5 is located on chromosome 22. There are three human FAM19A5 (UniProt: Q7Z5A7) isoforms, which are believed to be produced by alternative splicing: isoform 1 (UniProt: Q7Z5A7-1), which consists of 132 amino acids; isoform 2 (UniProt: Q7Z5A7-2), which consists of 125 amino acids; and isoform 3 (UniProt: Q7Z5A7-3), which consists of 53 amino acids. Human FAM19A5 protein is believed to exist as both membrane bound and soluble (secreted) forms. Isoform 1 is believed to be a membrane protein with one transmembrane region. Isoform 2, which was reported in Tang T. Y. et al., Genomics 83(4):727-34 (2004) as a secreted protein (soluble), contains a signal peptide at amino acid positions 1-25. Isoform 3 is predicted based on EST data. Below are the amino acid sequences of the three known human FAM19A5 isoforms.

(I) Isoform 1 (UniProt: Q7Z5A7-1, transmembrane protein): this isoform has been chosen as the canonical sequence.

(SEQ ID NO: 1) MAPSPRTGSRQDATALPSMSSTFWAFMILASLLIAYCSQLAAGTCEIVTL DRDSSQPRRTIARQTARCACRKGQIAGTTRARPACVDARIIKTKQWCDML PCLEGEGCDLLINRSGWTCTQPGGRIKTTTVS (II) Isoform 2 (UniProt: Q7Z5A7-2, soluble protein):

(SEQ ID NO: 2) MQLLKALWALAGAALCCFLVLVIHAQFLKEGQLAAGTCEIVTLDRDSSQP RRTIARQTARCACRKGQIAGTTRARPACVDARIIKTKQWCDMLPCLEGEG CDLLINRSGWTCTQPGGRIKTTTVS

(III) Isoform 3 (UniProt: Q7Z5A7-3):

(SEQ ID NO: 3) MYHHREWPARIIKTKQWCDMLPCLEGEGCDLLINRSGWTCTQPGGRIKTT TVS

The term “FAM19A5” includes any variants or isoforms of FAM19A5 which are naturally expressed by cells. Accordingly, antibodies described herein can cross-react with different isoforms in the same species (e.g., different isoforms of human FAM19A5), or cross-react with FAM19A5 from species other than human (e.g., mouse FAM19A5). Alternatively, the antibodies can be specific for human FAM19A5 and cannot exhibit any cross-reactivity with other species. FAM19A5, or any variants and isoforms thereof, can either be isolated from cells or tissues which naturally express them or be recombinantly produced. The polynucleotide encoding human FAM19A5 has the GenBank Accession No. BC039396 and the following sequence:

TABLE 1A Polynucleotide sequence of human FAM19A5 Polynucleotide sequence (SEQ ID NO: 4) FAM19A5 ggcggcggag gatggcgcgc gcggggcccg cacgtggagg ccggcgcggg (GenBank ggcgcgggca gggccggctg ctgagacgcg ctgctgcccc ccgcgcgggc Accession No. gccgcggctt caatggcgcc atcgcccagg accggcagcc ggcaagatgc BC039396) gaccgccctg cccagcatgt cctcaacttt ctgggcgttc atgatcctgg ccagcctgct catcgcctac tgcagtcagc tggccgccgg cacctgtgag attgtgacct tggaccggga cagcagccag cctcggagga cgatcgcccg gcagaccgcc cgctgtgcgt gtagaaaggg gcagatcgcc ggcaccacga gagcccggcc cgcctgtgtg gacgcaagaa tcatcaagac caagcagtgg tgtgacatgc ttccgtgtct ggagggggaa ggctgcgact tgttaatcaa ccggtcaggc tggacgtgca cgcagcccgg cgggaggata aagaccacca cggtctcctg acaaacacag cccctgaggg ggccccggga gtggccttgg ctccctggag agcccacgtc tcagccacag ttctccactc gcctcggact tcacccgttc tctgccgccc gcccactccg tttccctgtg gtccgtgaag gacggcctca ggccttggca tcctgagctt cggtctgtcc agccgacccg aggaggccgg actcagacac ataggcgggg ggcggcacct ggcatcagca atacgcagtc tgtgggagcc cggccgcgcc cagcccccgc cgaccgtggc gttggccctg ctgtcctcag aggaggagga ggaggaggca gctccggcag ccacagaagg ctgcagccca gcccgcctga gacacgacgc ctgccccagg ggactgtcag gcacagaagc ggcctcctcc cgtgccccag actgtccgaa ttgcttttat tttcttatac tttcagtata ctccatagac caaagagcaa aatctatctg aacctggacg caccctcact gtcagggtcc ctggggtcgc ttgtgcgggc gggagggcaa tggtggcaga gacatgctgg tggccccggc ggagcggaga gggcggccgt ggtggaggcc tccaccccag gagcaccccg cacaccctcg gaggacgggc ttcggctgcg cggaggccgt ggcacacctg cgggaggcag cgacggcccc cacgcagacg ccgggaacgc aggccgcttt attcctctgt acttagatca acttgaccgt actaaaatcc ctttctgttt taaccagtta aacatgcctc ttctacagct ccatttttga tagttggata atccagtatc tgccaagagc atgttgggtc tcccgtgact gctgcctcat cgatacccca tttagctcca gaaagcaaag aaaactcgag taacacttgt ttgaaagaga tcattaaatg tattttgcaa agcccaaaaa aaaaaaaaaa a

The term “antagonist against a FAM19A5 protein” refers to all antagonists that suppress the expression of the FAM19A5 protein. Such antagonist can be a peptide, nucleic acid, or a compound. More specifically, the antagonist can be an antisense-oligonucleotide, siRNA, shRNA, miRNA, dsRNA, aptamer, PNA (peptide nucleic acid) targeting FAM19A5, or a vector including the same. In some embodiments, the antagonist can be an antibody, or an antigen-binding portion thereof, that specifically binds to the FAM19A5 protein.

The terms “antibody” and “antibodies” are terms of art and can be used interchangeably herein and refer to a molecule with an antigen binding site that specifically binds an antigen. The terms as used to herein include whole antibodies and any antigen binding fragments (i.e., “antigen-binding portions”) or single chains thereof. An “antibody” refers, in one embodiment, to a glycoprotein comprising at least two heavy (H) chains and two light (L) chains inter-connected by disulfide bonds, or an antigen-binding portion thereof. In another embodiment, an “antibody” refers to a single chain antibody comprising a single variable domain, e.g., VHH domain. Each heavy chain is comprised of a heavy chain variable region (abbreviated herein as VH) and a heavy chain constant region. In certain naturally-occurring antibodies, the heavy chain constant region is comprised of three domains, CH1, CH2 and CH3. In certain naturally-occurring antibodies, each light chain is comprised of a light chain variable region (abbreviated herein as VL) and a light chain constant region. The light chain constant region is comprised of one domain, CL.

The VH and VL regions can be further subdivided into regions of hypervariability, termed complementarity determining regions (CDR), interspersed with regions that are more conserved, termed framework regions (FR). Each VH and VL is composed of three CDRs and four FRs, arranged from amino-terminus to carboxy-terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, and FR4. The variable regions of the heavy and light chains contain a binding domain that interacts with an antigen. The constant regions of the antibodies can mediate the binding of the immunoglobulin to host tissues or factors, including various cells of the immune system (e.g., effector cells) and the first component (C1q) of the classical complement system.

The term “Kabat numbering” and like terms are recognized in the art and refer to a system of numbering amino acid residues in the heavy and light chain variable regions of an antibody, or an antigen-binding portion thereof. In certain aspects, the CDRs of an antibody can be determined according to the Kabat numbering system (see, e.g., Kabat E A & Wu T T (1971) Ann NY Acad Sci 190: 382-391 and Kabat E A et al., (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242). Using the Kabat numbering system, CDRs within an antibody heavy chain molecule are typically present at amino acid positions 31 to 35, which optionally can include one or two additional amino acids, following 35 (referred to in the Kabat numbering scheme as 35A and 35B) (CDR1), amino acid positions 50 to 65 (CDR2), and amino acid positions 95 to 102 (CDR3). Using the Kabat numbering system, CDRs within an antibody light chain molecule are typically present at amino acid positions 24 to 34 (CDR1), amino acid positions 50 to 56 (CDR2), and amino acid positions 89 to 97 (CDR3). In a specific embodiment, the CDRs of the antibodies described herein have been determined according to the Kabat numbering scheme.

The phrases “amino acid position numbering as in Kabat,” “Kabat position,” and grammatical variants thereof refer to the numbering system used for heavy chain variable domains or light chain variable domains of the compilation of antibodies in Kabat et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, Md. (1991). Using this numbering system, the actual linear amino acid sequence can contain fewer or additional amino acids corresponding to a shortening of, or insertion into, a FW or CDR of the variable domain. For example, a heavy chain variable domain can include a single amino acid insert (residue 52a according to Kabat) after residue 52 of H2 and inserted residues (e.g., residues 82a, 82b, and 82c, etc. according to Kabat) after heavy chain FW residue 82. See TABLE 1B.

TABLE 1B Loop Kabat AbM Chothia L1 L24-L34  L24-L34 L24-L34 L2 L50-L56  L50-L56 L50-L56 L3 L89-L97  L89-L97 L89-L97 H1 H31-H35B  H26-H35B       H26-H32 . . . 34 (Kabat Numbering) H1 H31-H35  H26-H35 H26-H32 (Chothia Numbering) H2 H50-H65  H50-H58 H52-H56 H3 H95-H102  H95-H102  H95-H102

The Kabat numbering of residues can be determined for a given antibody by alignment at regions of homology of the sequence of the antibody with a “standard” Kabat numbered sequence. Chothia refers instead to the location of the structural loops (Chothia and Lesk, J. Mol. Biol. 196:901-917 (1987)). The end of the Chothia CDR-H1 loop when numbered using the Kabat numbering convention varies between H32 and H34 depending on the length of the loop (this is because the Kabat numbering scheme places the insertions at H35A and H35B; if neither 35A nor 35B is present, the loop ends at 32; if only 35A is present, the loop ends at 33; if both 35A and 35B are present, the loop ends at 34). The AbM hypervariable regions represent a compromise between the Kabat CDRs and Chothia structural loops, and are used by Oxford Molecular's AbM antibody modeling software.

IMGT (ImMunoGeneTics) also provides a numbering system for the immunoglobulin variable regions, including the CDRs. See, e.g., Lefranc, M. P. et al., Dev. Comp. Immunol. 27: 55-77(2003), which is herein incorporated by reference. The IMGT numbering system was based on an alignment of more than 5,000 sequences, structural data, and characterization of hypervariable loops and allows for easy comparison of the variable and CDR regions for all species. According to the IMGT numbering schema VH-CDR1 is at positions 26 to 35, VH-CDR2 is at positions 51 to 57, VH-CDR3 is at positions 93 to 102, VL-CDR1 is at positions 27 to 32, VL-CDR2 is at positions 50 to 52, and VL-CDR3 is at positions 89 to 97.

For all heavy chain constant region amino acid positions discussed in the present disclosure, numbering is according to the EU index first described in Edelman et al., 1969, Proc. Natl. Acad. Sci. USA 63(1):78-85, describing the amino acid sequence of myeloma protein EU, which is the first human lgG1 sequenced. The EU index of Edelman et al. is also set forth in Kabat et al., 1991, Sequences of Proteins of Immunological Interest, 5th Ed., United States Public Health Service, National Institutes of Health, Bethesda. Thus, the phrases “EU index as set forth in Kabat” or “EU index of Kabat” and “position . . . according to the EU index as set forth in Kabat,” and grammatical variants thereof refer to the residue numbering system based on the human lgG1 EU antibody of Edelman et al. as set forth in Kabat 1991.

The numbering system used for the variable domains (both heavy chain and light chain) and light chain constant region amino acid sequence is that set forth in Kabat 1991.

Antibodies can be of any type (e.g., IgG, IgE, IgM, IgD, IgA, or IgY), any class (e.g., IgD, IgG2, IgG3, IgG4, IgA1, or IgA2), or any subclass (e.g., IgG1, IgG2, IgG3, and IgG4 in humans; and IgG1, IgG2a, IgG2b, and IgG3 in mice) of immunoglobulin molecule. Immunoglobulins, e.g., IgG1, exist in several allotypes, which differ from each other in at most a few amino acids. An antibody disclosed herein can be from any of the commonly known isotypes, classes, subclasses, or allotypes. In certain embodiments, the antibodies described herein are of the IgG1, IgG2, IgG3, or IgG4 subclass or any hybrid thereof. In certain embodiments, the antibodies are of the human IgG1 subclass or the human IgG2 or human IgG4 subclass.

“Antibody” includes, by way of example, both naturally-occurring and non-naturally-occurring antibodies; monoclonal and polyclonal antibodies; chimeric and humanized antibodies; human and non-human antibodies; wholly synthetic antibodies; single chain antibodies; monospecific antibodies; multispecific antibodies (including bispecific antibodies); tetrameric antibodies comprising two heavy chain and two light chain molecules; an antibody light chain monomer; an antibody heavy chain monomer; an antibody light chain dimer, an antibody heavy chain dimer; an antibody light chain-antibody heavy chain pair; intrabodies; heteroconjugate antibodies; monovalent antibodies; camelized antibodies; affybodies; anti-idiotypic (anti-Id) antibodies (including, e.g., anti-anti-Id antibodies), and single-domain antibodies (sdAbs), which include binding molecules consisting of a single monomeric variable antibody domain that are fully capable of antigen binding (e.g., a VH domain or a VL domain). Harmen M. M. and Haard H. J. Appl Microbiol Biotechnol. 77(1): 13-22 (2007)).

The term “antigen-binding portion” of an antibody, as used herein, refers to one or more fragments of an antibody that retain the ability to specifically bind to an antigen (e.g., human FAM19A5). Such “fragments” are, for example between about 8 and about 1500 amino acids in length, suitably between about 8 and about 745 amino acids in length, suitably about 8 to about 300, for example about 8 to about 200 amino acids, or about 10 to about 50 or 100 amino acids in length. It has been shown that the antigen-binding function of an antibody can be performed by fragments of a full-length antibody. Examples of binding fragments encompassed within the term “antigen-binding portion” of an antibody, e.g., an anti-FAM19A5 antibody described herein, include (i) a Fab fragment, a monovalent fragment consisting of the VL, VH, CL, and CH1 domains; (ii) a F(ab′)2 fragment, a bivalent fragment comprising two Fab fragments linked by a disulfide bridge at the hinge region; (iii) a Fd fragment consisting of the VH and CH1 domains; (iv) a Fv fragment consisting of the VL and VH domains of a single arm of an antibody, and disulfide-linked Fvs (sdFv); (v) a dAb fragment (Ward et al., (1989) Nature 341:544-546), which consists of a VH domain; and (vi) an isolated complementarity determining region (CDR) or (vii) a combination of two or more isolated CDRs which can optionally be joined by a synthetic linker. Furthermore, although the two domains of the Fv fragment, VL and VH, are coded for by separate genes, they can be joined, using recombinant methods, by a synthetic linker that enables them to be made as a single protein chain in which the VL and VH regions pair to form monovalent molecules (known as single chain Fv (scFv)); see, e.g., Bird et al. (1988) Science 242:423-426; and Huston et al. (1988) Proc. Natl. Acad. Sci. USA 85:5879-5883). Such single chain antibodies are also intended to be encompassed within the term “antigen-binding portion” of an antibody. These antibody fragments are obtained using conventional techniques known to those with skill in the art, and the fragments are screened for utility in the same manner as are intact antibodies. Antigen-binding portions can be produced by recombinant DNA techniques, or by enzymatic or chemical cleavage of intact immunoglobulins.

As used herein, the terms “variable region” or “variable domain” are used interchangeably and are common in the art. The variable region typically refers to a portion of an antibody, generally, a portion of a light or heavy chain, typically about the amino-terminal 110 to 120 amino acids in the mature heavy chain and about 90 to 115 amino acids in the mature light chain, which differ extensively in sequence among antibodies and are used in the binding and specificity of a particular antibody for its particular antigen. The variability in sequence is concentrated in those regions called complementarity determining regions (CDRs) while the more highly conserved regions in the variable domain are called framework regions (FR).

Without wishing to be bound by any particular mechanism or theory, it is believed that the CDRs of the light and heavy chains are primarily responsible for the interaction and specificity of the antibody with antigen. In certain embodiments, the variable region is a human variable region. In certain embodiments, the variable region comprises rodent or murine CDRs and human framework regions (FRs). In particular embodiments, the variable region is a primate (e.g., non-human primate) variable region. In certain embodiments, the variable region comprises rodent or murine CDRs and primate (e.g., non-human primate) framework regions (FRs).

As used herein, the term “heavy chain” when used in reference to an antibody can refer to any distinct type, e.g., alpha (α), delta (δ), epsilon (ε), gamma (γ) and mu (μ), based on the amino acid sequence of the constant domain, which give rise to IgA, IgD, IgE, IgG and IgM classes of antibodies, respectively, including subclasses of IgG, e.g., IgG1, IgG2, IgG3 and IgG4.

As used herein, the term “light chain” when used in reference to an antibody can refer to any distinct type, e.g., kappa (κ) or lambda (λ) based on the amino acid sequence of the constant domains. Light chain amino acid sequences are well known in the art. In specific embodiments, the light chain is a human light chain.

The terms “VL” and “VL domain” are used interchangeably to refer to the light chain variable region of an antibody.

The terms “VH” and “VH domain” are used interchangeably to refer to the heavy chain variable region of an antibody.

As used herein, the term “constant region” or “constant domain” are interchangeable and have its meaning common in the art. The constant region is an antibody portion, e.g., a carboxyl terminal portion of a light and/or heavy chain which is not directly involved in binding of an antibody to antigen but which can exhibit various effector functions, such as interaction with the Fc receptor. The constant region of an immunoglobulin molecule generally has a more conserved amino acid sequence relative to an immunoglobulin variable domain.

An “Fc region” (fragment crystallizable region) or “Fc domain” or “Fc” refers to the C-terminal region of the heavy chain of an antibody that mediates the binding of the immunoglobulin to host tissues or factors, including binding to Fc receptors located on various cells of the immune system (e.g., effector cells) or to the first component (C1q) of the classical complement system. Thus, an Fc region comprises the constant region of an antibody excluding the first constant region immunoglobulin domain (e.g., CH1 or CL). In IgG, IgA and IgD antibody isotypes, the Fc region comprises two identical protein fragments, derived from the second (CH2) and third (CH3) constant domains of the antibody's two heavy chains; IgM and IgE Fc regions comprise three heavy chain constant domains (CH domains 2-4) in each polypeptide chain. For IgG, the Fc region comprises immunoglobulin domains Cγ2 and Cγ3 and the hinge between Cγ1 and Cγ2. Although the boundaries of the Fc region of an immunoglobulin heavy chain might vary, the human IgG heavy chain Fc region is usually defined to stretch from an amino acid residue at position C226 or P230 (or amino acid between these two amino acids) to the carboxy-terminus of the heavy chain, wherein the numbering is according to the EU index as in Kabat. The CH2 domain of a human IgG Fc region extends from about amino acid 231 to about amino acid 340, whereas the CH3 domain is positioned on C-terminal side of a Cm domain in an Fc region, i.e., it extends from about amino acid 341 to about amino acid 447 of an IgG. As used herein, the Fc region can be a native sequence Fc, including any allotypic variant, or a variant Fc (e.g., a non-naturally-occurring Fc). Fc can also refer to this region in isolation or in the context of an Fc-comprising protein polypeptide such as a “binding protein comprising an Fc region,” also referred to as an “Fc fusion protein” (e.g., an antibody or immunoadhesion).

A “native sequence Fc region” or “native sequence Fc” comprises an amino acid sequence that is identical to the amino acid sequence of an Fc region found in nature. Native sequence human Fc regions include a native sequence human IgG1 Fc region; native sequence human IgG2 Fc region; native sequence human IgG3 Fc region; and native sequence human IgG4 Fc region as well as naturally-occurring variants thereof. Native sequence Fc includes the various allotypes of Fes (see, e.g., Jefferis et al. (2009) mAbs 1:1; Vidarsson G. et al. Front Immunol. 5:520 (published online Oct. 20, 2014)).

An “Fc receptor” or “FcR” is a receptor that binds to the Fc region of an immunoglobulin. FcRs that bind to an IgG antibody comprise receptors of the FcγR family, including allelic variants and alternatively spliced forms of these receptors. The FcγR family consists of three activating (FcγRI, FcγRIII, and FcγRIV in mice; FcγRIA, FcγRIIA, and FcγRIIIA in humans) and one inhibitory (FcγRIIB) receptor. Human IgG1 binds to most human Fc receptors and elicits the strongest Fc effector functions. It is considered equivalent to murine IgG2a with respect to the types of activating Fc receptors that it binds to. Conversely, human IgG4 elicits the least Fc effector functions. Vidarsson G. et al. Front Immunol. 5:520 (published online Oct. 20, 2014).

The constant region can be manipulated, e.g., by recombinant technology, to eliminate one or more effector functions. An “effector function” refers to the interaction of an antibody Fc region with an Fc receptor or ligand, or a biochemical event that results therefrom. Exemplary “effector functions” include C1q binding, complement dependent cytotoxicity (CDC), Fc receptor binding, FcγR-mediated effector functions such as ADCC and antibody dependent cell-mediated phagocytosis (ADCP), and down regulation of a cell surface receptor (e.g., the B cell receptor; BCR). Such effector functions generally require the Fc region to be combined with a binding domain (e.g., an antibody variable domain). Accordingly, the term “a constant region without the Fc function” include constant regions with reduced or without one or more effector functions mediated by Fc region.

Effector functions of an antibody can be reduced or avoided by different approaches. Effector functions of an antibody can be reduced or avoided by using antibody fragments lacking the Fc region (e.g., such as a Fab, F(ab′)₂, single chain Fv (scFv), or a sdAb consisting of a monomeric VH or VL domain). Alternatively, the so-called aglycosylated antibodies can be generated by removing sugars that are linked to particular residues in the Fc region to reduce the effector functions of an antibody while retaining other valuable attributes of the Fc region (e.g., prolonged half-life and heterodimerization). Aglycosylated antibodies can be generated by, for example, deleting or altering the residue the sugar is attached to, removing the sugars enzymatically, producing the antibody in cells cultured in the presence of a glycosylation inhibitor, or by expressing the antibody in cells unable to glycosylate proteins (e.g., bacterial host cells). See, e.g., U.S. Pub. No. 20120100140. Another approach is to employ Fc regions from an IgG subclass that have reduced effector function, for example, IgG2 and IgG4 antibodies are characterized by having lower levels of Fc effector functions than IgG1 and IgG3. The residues most proximal to the hinge region in the CH2 domain of the Fc part are responsible for effector functions of antibodies as it contains a largely overlapping binding site for C1q (complement) and IgG-Fc receptors (FcγR) on effector cells of the innate immune system. Vidarsson G. et al. Front Immunol. 5:520 (published online Oct. 20, 2014). Accordingly, antibodies with reduced or without Fc effector functions can be prepared by generating, e.g., a chimeric Fc region which comprises a CH2 domain from an IgG antibody of the IgG4 isotype and a CH3 domain from an IgG antibody of the IgG1 isotype, or a chimeric Fc region which comprises hinge region from IgG2 and CH2 region from IgG4 (see, e.g., Lau C. et al. J. Immunol. 191:4769-4777 (2013)), or an Fc region with mutations that result in altered Fc effector functions, e.g., reduced or no Fc functions. Such Fc regions with mutations are known in the art. See, e.g., U.S. Pub. No. 20120100140 and U.S. and PCT applications cited therein and An et al. mAbs 1:6, 572-579 (2009); the disclosure of which are incorporated by reference to their entirety.

A “hinge”, “hinge domain” or “hinge region” or “antibody hinge region” refers to the domain of a heavy chain constant region that joins the CH1 domain to the CH2 domain and includes the upper, middle, and lower portions of the hinge (Roux et al. J. Immunol. 1998 161:4083). The hinge provides varying levels of flexibility between the binding and effector regions of an antibody and also provides sites for intermolecular disulfide bonding between the two heavy chain constant regions. As used herein, a hinge starts at Glu216 and ends at Gly237 for all IgG isotypes (Roux et al., 1998 J Immunol 161:4083). The sequences of wild-type IgG1, IgG2, IgG3 and IgG4 hinges are known in the art. See, e.g., Kabat E A et al., (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242; Vidarsson G. et al. Front Immunol. 5:520 (published online Oct. 20, 2014).

The term “CH1 domain” refers to the heavy chain constant region linking the variable domain to the hinge in a heavy chain constant domain. As used herein, a CH1 domain starts at A118 and ends at V215. The term “CH1 domain” includes wildtype CH1 domains, as well as naturally existing variants thereof (e.g., allotypes). CH1 domain sequences of IgG1, IgG2, IgG3, and IgG4 (including wildtype and allotypes) are known in the art. See, e.g., Kabat E A et al., (1991) supra and Vidarsson G. et al. Front Immunol. 5:520 (published online Oct. 20, 2014). Exemplary CH1 domains include CH1 domains with mutations that modify a biological activity of an antibody, e.g., half-life, e.g., described in U.S. Pub. No. 20120100140 and U.S. patents and publications and PCT publications cited therein.

The term “CH2 domain” refers to the heavy chain constant region linking the hinge to the CH3 domain in a heavy chain constant domain. As used herein, a CH2 domain starts at P238 and ends at K340. The term “CH2 domain” includes wildtype CH2 domains, as well as naturally existing variants thereof (e.g., allotypes). CH2 domain sequences of IgG1, IgG2, IgG3, and IgG4 (including wildtype and allotypes) are known in the art. See, e.g., Kabat E A et al., (1991) supra and Vidarsson G. et al. Front Immunol. 5:520 (published online Oct. 20, 2014). Exemplary CH2 domains include CH2 domains with mutations that modify a biological activity of an antibody, e.g., half-life and/or reduced Fc effector function, e.g., described in U.S. Pub. No. 20120100140 and U.S. patents and publications and PCT publications cited therein.

The term “CH3 domain” refers to the heavy chain constant region that is C-terminal to the CH2 domain in a heavy chain constant domain. As used herein, a CH3 domain starts at G341 and ends at K447. The term “CH3 domain” includes wildtype CH3 domains, as well as naturally existing variants thereof (e.g., allotypes). CH3 domain sequences of IgG1, IgG2, IgG3, and IgG4 (including wildtype and allotypes) are known in the art. See, e.g., Kabat E A et al., (1991) supra and Vidarsson G. et al. Front Immunol. 5:520 (published online Oct. 20, 2014). Exemplary CH3 domains include CH3 domains with mutations that modify a biological activity of an antibody, e.g., half-life, e.g., described in U.S. Pub. No. 20120100140 and U.S. patents and publications and PCT publications cited therein.

As used herein, “isotype” refers to the antibody class (e.g., IgG1, IgG2, IgG3, IgG4, IgM, IgA1, IgA2, IgD, and IgE antibody) that is encoded by the heavy chain constant region genes.

“Allotype” refers to naturally-occurring variants within a specific isotype group, which variants differ in a few amino acids (see, e.g., Jefferis et al. (2009) mAbs 1:1). Antibodies described herein can be of any allotype. Allotypes of IgG1, IgG2, IgG3, and IgG4 are known in the art. See, e.g., Kabat E A et al., (1991) supra; Vidarsson G. et al. Front Immunol. 5:520 (published online Oct. 20, 2014); and Lefranc M P, mAbs 1:4, 1-7(2009).

The phrases “an antibody recognizing an antigen” and “an antibody specific for an antigen” are used interchangeably herein with the term “an antibody which binds specifically to an antigen.”

An “isolated antibody,” as used herein, is intended to refer to an antibody which is substantially free of other antibodies having different antigenic specificities (e.g., an isolated antibody that specifically binds to FAM19A5 is substantially free of antibodies that specifically bind antigens other than FAM19A5). An isolated antibody that specifically binds to an epitope of FAM19A5 can, however, have cross-reactivity to other FAM19A5 proteins from different species.

“Binding affinity” generally refers to the strength of the sum total of non-covalent interactions between a single binding site of a molecule (e.g., an antibody) and its binding partner (e.g., an antigen). Unless indicated otherwise, as used herein, “binding affinity” refers to intrinsic binding affinity which reflects a 1:1 interaction between members of a binding pair (e.g., antibody and antigen). The affinity of a molecule X for its partner Y can generally be represented by the dissociation constant (K_(D)). Affinity can be measured and/or expressed in a number of ways known in the art, including, but not limited to, equilibrium dissociation constant (K_(D)), and equilibrium association constant (K_(A)). The K_(D) is calculated from the quotient of k_(off)/k_(on) and is expressed as a molar concentration (M), whereas K_(A) is calculated from the quotient of k_(on)/k_(off). k_(on) refers to the association rate constant of, e.g., an antibody to an antigen, and k_(off) refers to the dissociation of, e.g., an antibody to an antigen. The k_(on) and k_(off) can be determined by techniques known to one of ordinary skill in the art, such as immunoassays (e.g., enzyme-linked immunosorbent assay (ELISA)), BIACORE® or kinetic exclusion assay (KinExA®).

As used herein, the terms “specifically binds,” “specifically recognizes,” “specific binding,” “selective binding,” and “selectively binds,” are analogous terms in the context of antibodies and refer to molecules (e.g., antibodies) that bind to an antigen (e.g., epitope or immune complex) as such binding is understood by one skilled in the art. For example, a molecule that specifically binds to an antigen can bind to other peptides or polypeptides, generally with lower affinity as determined by, e.g., immunoassays, BIACORE®, KinExA® 3000 instrument (Sapidyne Instruments, Boise, Id.), or other assays known in the art. In a specific embodiment, molecules that specifically bind to an antigen bind to the antigen with a K_(A) that is at least 2 logs, 2.5 logs, 3 logs, 4 logs or greater than the K_(A) when the molecules bind to another antigen.

Antibodies typically bind specifically to their cognate antigen with high affinity, reflected by a dissociation constant (K_(D)) of 10⁻⁵ to 10⁻¹¹ M or less. Any K_(D) greater than about 10⁻⁴ M is generally considered to indicate nonspecific binding. As used herein, an antibody that “binds specifically” to an antigen refers to an antibody that binds to the antigen and substantially identical antigens with high affinity, which means having a K_(D) of 10⁻⁷ M or less, preferably 10⁻⁸ M or less, even more preferably 10⁻⁹ M or less, and most preferably between 10⁻⁸ M and 10⁻¹⁰ M or less, when determined by, e.g., immunoassays (e.g., ELISA) or surface plasmon resonance (SPR) technology in a BIACORE™ 2000 instrument using the predetermined antigen, but does not bind with high affinity to unrelated antigens.

As used herein, the term “antigen” refers to any natural or synthetic immunogenic substance, such as a protein, peptide, or hapten. An antigen can be FAM19A5 or a fragment thereof.

As used herein, an “epitope” is a term in the art and refers to a localized region of an antigen to which an antibody can specifically bind. An epitope can be, for example, contiguous amino acids of a polypeptide (linear or contiguous epitope) or an epitope can, for example, come together from two or more non-contiguous regions of a polypeptide or polypeptides (conformational, non-linear, discontinuous, or non-contiguous epitope). Epitopes formed from contiguous amino acids are typically, but not always, retained on exposure to denaturing solvents, whereas epitopes formed by tertiary folding are typically lost on treatment with denaturing solvents. An epitope typically includes at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 20 amino acids in a unique spatial conformation. Methods for determining what epitopes are bound by a given antibody (i.e., epitope mapping) are well known in the art and include, for example, immunoblotting and immunoprecipitation assays, wherein overlapping or contiguous peptides from (e.g., from FMAM19A5) are tested for reactivity with a given antibody (e.g., anti-FAM19A5 antibody). Methods of determining spatial conformation of epitopes include techniques in the art and those described herein, for example, x-ray crystallography, 2-dimensional nuclear magnetic resonance and HDX-MS (see, e.g., Epitope Mapping Protocols in Methods in Molecular Biology, Vol. 66, G. E. Morris, Ed. (1996)).

In certain embodiments, the epitope to which an antibody binds can be determined by, e.g., NMR spectroscopy, X-ray diffraction crystallography studies, ELISA assays, hydrogen/deuterium exchange coupled with mass spectrometry (e.g., liquid chromatography electrospray mass spectrometry), array-based oligo-peptide scanning assays, and/or mutagenesis mapping (e.g., site-directed mutagenesis mapping). For X-ray crystallography, crystallization can be accomplished using any of the known methods in the art (e.g., Giege R et al., (1994) Acta Crystallogr D Biol Crystallogr 50(Pt 4): 339-350; McPherson A (1990) Eur J Biochem 189: 1-23; Chayen N E (1997) Structure 5: 1269-1274; McPherson A (1976) J Biol Chem 251: 6300-6303). Antibody:antigen crystals can be studied using well known X-ray diffraction techniques and can be refined using computer software such as X-PLOR (Yale University, 1992, distributed by Molecular Simulations, Inc.; see, e.g., Meth Enzymol (1985) volumes 114 & 115, eds Wyckoff H W et al.; U.S. 2004/0014194), and BUSTER (Bricogne G (1993) Acta Crystallogr D Biol Crystallogr 49(Pt 1): 37-60; Bricogne G (1997) Meth Enzymol 276A: 361-423, ed Carter C W; Roversi P et al., (2000) Acta Crystallogr D Biol Crystallogr 56(Pt 10): 1316-1323). Mutagenesis mapping studies can be accomplished using any method known to one of skill in the art. See, e.g., Champe M et al., (1995) J Biol Chem 270: 1388-1394 and Cunningham B C & Wells J A (1989) Science 244: 1081-1085 for a description of mutagenesis techniques, including alanine scanning mutagenesis techniques.

The term “epitope mapping” refers to the process of identification of the molecular determinants for antibody-antigen recognition.

The term “binds to the same epitope” with reference to two or more antibodies means that the antibodies bind to the same segment of amino acid residues, as determined by a given method. Techniques for determining whether antibodies bind to the “same epitope on FAM19A5” with the antibodies described herein include, for example, epitope mapping methods, such as, x-ray analyses of crystals of antigen:antibody complexes which provides atomic resolution of the epitope and hydrogen/deuterium exchange mass spectrometry (HDX-MS). Other methods monitor the binding of the antibody to antigen fragments or mutated variations of the antigen where loss of binding due to a modification of an amino acid residue within the antigen sequence is often considered an indication of an epitope component. In addition, computational combinatorial methods for epitope mapping can also be used. These methods rely on the ability of the antibody of interest to affinity isolate specific short peptides from combinatorial phage display peptide libraries. Antibodies having the same VH and VL or the same CDR1, 2 and 3 sequences are expected to bind to the same epitope.

Antibodies that “compete with another antibody for binding to a target” refer to antibodies that inhibit (partially or completely) the binding of the other antibody to the target. Whether two antibodies compete with each other for binding to a target, i.e., whether and to what extent one antibody inhibits the binding of the other antibody to a target, can be determined using known competition experiments. In certain embodiments, an antibody competes with, and inhibits binding of another antibody to a target by at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 100%. The level of inhibition or competition can be different depending on which antibody is the “blocking antibody” (i.e., the cold antibody that is incubated first with the target). Competition assays can be conducted as described, for example, in Ed Harlow and David Lane, Cold Spring Harb Protoc; 2006; doi: 10.1101/pdb.prot4277 or in Chapter 11 of “Using Antibodies” by Ed Harlow and David Lane, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., USA 1999. Competing antibodies bind to the same epitope, an overlapping epitope or to adjacent epitopes (e.g., as evidenced by steric hindrance).

Other competitive binding assays include: solid phase direct or indirect radioimmunoassay (MA), solid phase direct or indirect enzyme immunoassay (EIA), sandwich competition assay (see Stahli et al., Methods in Enzymology 9:242 (1983)); solid phase direct biotin-avidin EIA (see Kirkland et al., J. Immunol. 137:3614 (1986)); solid phase direct labeled assay, solid phase direct labeled sandwich assay (see Harlow and Lane, Antibodies: A Laboratory Manual, Cold Spring Harbor Press (1988)); solid phase direct label RIA using 1-125 label (see Morel et al., Mol. Immunol. 25(1):7 (1988)); solid phase direct biotin-avidin EIA (Cheung et al., Virology 176:546 (1990)); and direct labeled MA. (Moldenhauer et al., Scand. J. Immunol. 32:77 (1990)).

A “bispecific” or “bifunctional antibody” is an artificial hybrid antibody having two different heavy/light chain pairs and two different binding sites. Bispecific antibodies can be produced by a variety of methods including fusion of hybridomas or linking of Fab′ fragments. See, e.g., Songsivilai & Lachmann, Clin. Exp. Immunol. 79:315-321 (1990); Kostelny et al., J. Immunol. 148, 1547-1553 (1992).

The term “monoclonal antibody,” as used herein, refers to an antibody that displays a single binding specificity and affinity for a particular epitope or a composition of antibodies in which all antibodies display a single binding specificity and affinity for a particular epitope. Accordingly, the term “human monoclonal antibody” refers to an antibody or antibody composition that display(s) a single binding specificity and which has variable and optional constant regions derived from human germline immunoglobulin sequences. In one embodiment, human monoclonal antibodies are produced by a hybridoma which includes a B cell obtained from a transgenic non-human animal, e.g., a transgenic mouse, having a genome comprising a human heavy chain transgene and a light chain transgene fused to an immortalized cell.

The term “recombinant human antibody,” as used herein, includes all human antibodies that are prepared, expressed, created or isolated by recombinant means, such as (a) antibodies isolated from an animal (e.g., a mouse) that is transgenic or transchromosomal for human immunoglobulin genes or a hybridoma prepared therefrom, (b) antibodies isolated from a host cell transformed to express the antibody, e.g., from a transfectoma, (c) antibodies isolated from a recombinant, combinatorial human antibody library, and (d) antibodies prepared, expressed, created or isolated by any other means that involve splicing of human immunoglobulin gene sequences to other DNA sequences. Such recombinant human antibodies comprise variable and constant regions that utilize particular human germline immunoglobulin sequences are encoded by the germline genes, but include subsequent rearrangements and mutations which occur, for example, during antibody maturation. As known in the art (see, e.g., Lonberg (2005) Nature Biotech. 23(9): 1117-1125), the variable region contains the antigen binding domain, which is encoded by various genes that rearrange to form an antibody specific for a foreign antigen. In addition to rearrangement, the variable region can be further modified by multiple single amino acid changes (referred to as somatic mutation or hypermutation) to increase the affinity of the antibody to the foreign antigen. The constant region will change in further response to an antigen (i.e., isotype switch). Therefore, the rearranged and somatically mutated nucleic acid molecules that encode the light chain and heavy chain immunoglobulin polypeptides in response to an antigen cannot have sequence identity with the original nucleic acid molecules, but instead will be substantially identical or similar (i.e., have at least 80% identity).

A “human” antibody (HuMAb) refers to an antibody having variable regions in which both the framework and CDR regions are derived from human germline immunoglobulin sequences. Furthermore, if the antibody contains a constant region, the constant region also is derived from human germline immunoglobulin sequences. The antibodies described herein can include amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo). However, the term “human antibody”, as used herein, is not intended to include antibodies in which CDR sequences derived from the germline of another mammalian species, such as a mouse, have been grafted onto human framework sequences. The terms “human” antibodies and “fully human” antibodies are used synonymously.

A “humanized” antibody refers to an antibody in which some, most or all of the amino acids outside the CDR domains of a non-human antibody are replaced with corresponding amino acids derived from human immunoglobulins. In one embodiment of a humanized form of an antibody, some, most or all of the amino acids outside the CDR domains have been replaced with amino acids from human immunoglobulins, whereas some, most or all amino acids within one or more CDR regions are unchanged. Small additions, deletions, insertions, substitutions or modifications of amino acids are permissible as long as they do not abrogate the ability of the antibody to bind to a particular antigen. A “humanized” antibody retains an antigenic specificity similar to that of the original antibody.

A “chimeric antibody” refers to an antibody in which the variable regions are derived from one species and the constant regions are derived from another species, such as an antibody in which the variable regions are derived from a mouse antibody and the constant regions are derived from a human antibody.

The term “cross-reacts,” as used herein, refers to the ability of an antibody described herein to bind to FAM19A5 from a different species. For example, an antibody described herein that binds human FAM19A5 can also bind another species of FAM19A5 (e.g., mouse FAM19A5). As used herein, cross-reactivity can be measured by detecting a specific reactivity with purified antigen in binding assays (e.g., SPR, ELISA) or binding to, or otherwise functionally interacting with, cells physiologically expressing FAM19A5. Methods for determining cross-reactivity include standard binding assays as described herein, for example, by BIACORE® surface plasmon resonance (SPR) analysis using a BIACORE® 2000 SPR instrument (Biacore AB, Uppsala, Sweden), or flow cytometric techniques.

The term “naturally-occurring” as applied to an object herein refers to the fact that an object can be found in nature. For example, a polypeptide or polynucleotide sequence that is present in an organism (including viruses) that can be isolated from a source in nature and which has not been intentionally modified by man in the laboratory is naturally-occurring.

A “polypeptide” refers to a chain comprising at least two consecutively linked amino acid residues, with no upper limit on the length of the chain. One or more amino acid residues in the protein can contain a modification such as, but not limited to, glycosylation, phosphorylation or disulfide bond formation. A “protein” can comprise one or more polypeptides.

The term “nucleic acid molecule,” as used herein, is intended to include DNA molecules and RNA molecules. A nucleic acid molecule can be single-stranded or double-stranded, and can be cDNA.

“Conservative amino acid substitutions” refer to substitutions of an amino acid residue with an amino acid residue having a similar side chain. Families of amino acid residues having similar side chains have been defined in the art. These families include amino acids with basic side chains (e.g., lysine, arginine, histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine, tryptophan), nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine), beta-branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine). In certain embodiments, a predicted nonessential amino acid residue in an anti-TIM3 antibody is replaced with another amino acid residue from the same side chain family. Methods of identifying nucleotide and amino acid conservative substitutions which do not eliminate antigen binding are well-known in the art (see, e.g., Brummell et al., Biochem. 32: 1180-1187 (1993); Kobayashi et al. Protein Eng. 12(10):879-884 (1999); and Burks et al. Proc. Natl. Acad. Sci. USA 94:412-417 (1997)).

For nucleic acids, the term “substantial homology” indicates that two nucleic acids, or designated sequences thereof, when optimally aligned and compared, are identical, with appropriate nucleotide insertions or deletions, in at least about 80% of the nucleotides, at least about 90% to 95%, or at least about 98% to 99.5% of the nucleotides. Alternatively, substantial homology exists when the segments will hybridize under selective hybridization conditions, to the complement of the strand.

For polypeptides, the term “substantial homology” indicates that two polypeptides, or designated sequences thereof, when optimally aligned and compared, are identical, with appropriate amino acid insertions or deletions, in at least about 80% of the amino acids, at least about 90% to 95%, or at least about 98% to 99.5% of the amino acids.

The percent identity between two sequences is a function of the number of identical positions shared by the sequences (i.e., % homology=# of identical positions/total # of positions×100), taking into account the number of gaps, and the length of each gap, which need to be introduced for optimal alignment of the two sequences. The comparison of sequences and determination of percent identity between two sequences can be accomplished using a mathematical algorithm, as described in the non-limiting examples below.

The percent identity between two nucleotide sequences can be determined using the GAP program in the GCG software package (available at worldwideweb.gcg.com), using a NWSgapdna.CMP matrix and a gap weight of 40, 50, 60, 70, or 80 and a length weight of 1, 2, 3, 4, 5, or 6. The percent identity between two nucleotide or amino acid sequences can also be determined using the algorithm of E. Meyers and W. Miller (CABIOS, 4: 11-17 (1989)) which has been incorporated into the ALIGN program (version 2.0), using a PAM120 weight residue table, a gap length penalty of 12 and a gap penalty of 4. In addition, the percent identity between two amino acid sequences can be determined using the Needleman and Wunsch (J. Mol. Biol. (48):444-453 (1970)) algorithm which has been incorporated into the GAP program in the GCG software package (available at http://www.gcg.com), using either a Blossum 62 matrix or a PAM250 matrix, and a gap weight of 16, 14, 12, 10, 8, 6, or 4 and a length weight of 1, 2, 3, 4, 5, or 6.

The nucleic acid and protein sequences described herein can further be used as a “query sequence” to perform a search against public databases to, for example, identify related sequences. Such searches can be performed using the NBLAST and XBLAST programs (version 2.0) of Altschul, et al. (1990) J. Mol. Biol. 215:403-10. BLAST nucleotide searches can be performed with the NBLAST program, score=100, wordlength=12 to obtain nucleotide sequences homologous to the nucleic acid molecules described herein. BLAST protein searches can be performed with the XBLAST program, score=50, wordlength=3 to obtain amino acid sequences homologous to the protein molecules described herein. To obtain gapped alignments for comparison purposes, Gapped BLAST can be utilized as described in Altschul et al., (1997) Nucleic Acids Res. 25(17):3389-3402. When utilizing BLAST and Gapped BLAST programs, the default parameters of the respective programs (e.g., XBLAST and NBLAST) can be used. See worldwideweb.ncbi.nlm.nih.gov.

The nucleic acids can be present in whole cells, in a cell lysate, or in a partially purified or substantially pure form. A nucleic acid is “isolated” or “rendered substantially pure” when purified away from other cellular components or other contaminants, e.g., other cellular nucleic acids (e.g., the other parts of the chromosome) or proteins, by standard techniques, including alkaline/SDS treatment, CsCl banding, column chromatography, agarose gel electrophoresis and others well known in the art. See, F. Ausubel, et al., ed. Current Protocols in Molecular Biology, Greene Publishing and Wiley Interscience, New York (1987).

Nucleic acids, e.g., cDNA, can be mutated, in accordance with standard techniques to provide gene sequences. For coding sequences, these mutations, can affect amino acid sequence as desired. In particular, DNA sequences substantially homologous to or derived from native V, D, J, constant, switches and other such sequences described herein are contemplated (where “derived” indicates that a sequence is identical or modified from another sequence).

The term “vector,” as used herein, is intended to refer to a nucleic acid molecule capable of transporting another nucleic acid to which it has been linked. One type of vector is a “plasmid,” which refers to a circular double stranded DNA loop into which additional DNA segments can be ligated. Another type of vector is a viral vector, wherein additional DNA segments can be ligated into the viral genome. Certain vectors are capable of autonomous replication in a host cell into which they are introduced (e.g., bacterial vectors having a bacterial origin of replication and episomal mammalian vectors). Other vectors (e.g., non-episomal mammalian vectors) can be integrated into the genome of a host cell upon introduction into the host cell, and thereby are replicated along with the host genome. Moreover, certain vectors are capable of directing the expression of genes to which they are operatively linked. Such vectors are referred to herein as “recombinant expression vectors” (or simply, “expression vectors”). In general, expression vectors of utility in recombinant DNA techniques are often in the form of plasmids. In the present specification, “plasmid” and “vector” can be used interchangeably as the plasmid is the most commonly used form of vector. However, also included are other forms of expression vectors, such as viral vectors (e.g., replication defective retroviruses, adenoviruses and adeno-associated viruses), which serve equivalent functions.

The term “recombinant host cell” (or simply “host cell”), as used herein, is intended to refer to a cell that comprises a nucleic acid that is not naturally present in the cell, and can be a cell into which a recombinant expression vector has been introduced. It should be understood that such terms are intended to refer not only to the particular subject cell but to the progeny of such a cell. Because certain modifications can occur in succeeding generations due to either mutation or environmental influences, such progeny cannot, in fact, be identical to the parent cell, but are still included within the scope of the term “host cell” as used herein.

As used herein, the term “linked” refers to the association of two or more molecules. The linkage can be covalent or non-covalent. The linkage also can be genetic (i.e., recombinantly fused). Such linkages can be achieved using a wide variety of art recognized techniques, such as chemical conjugation and recombinant protein production.

The term “therapeutically effective amount” as used herein refers to an amount of a drug, alone or in combination with another therapeutic agent, effective to “treat” a disease or disorder in a subject or reduce the risk, potential, possibility or occurrence of a disease or disorder (e.g., liver fibrosis or pulmonary fibrosis). A “therapeutically effective amount” includes an amount of a drug or a therapeutic agent that provides some improvement or benefit to a subject having or at risk of having a disease or disorder associated with fibrosis. Thus, a “therapeutically effective” amount is an amount that reduces the risk, potential, possibility or occurrence of a disease or provides disorder or some alleviation, mitigation, and/or reduces at least one indicator (e.g., an onset of fibrosis or fibrotic tissue formation), and/or decrease in at least one clinical symptom of a disease or disorder associated with fibrosis.

II. Methods of Treating Fibrosis

Disclosed herein are methods of treating reducing, ameliorating, controlling, or inhibiting a fibrosis in a subject in need thereof, comprising administering to the subject an antagonist against FAM19A5. Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in response to certain injuries. Generally, acute wounds normally heal in an orderly and efficient manner through a process that is characterized by four distinct phases: hemostasis, inflammation, proliferation, and remodeling. Diegelmann R. F. et al., Front Biosci 9:283-289 (2004). However, where the injury is severe or repetitive, dysregulation of the wound healing process can occur, which is marked by excessive accumulation of extracellular matrix proteins (ECM) (e.g., collagen, glycoprotein, and proteoglycan) at the site of damage. This can result in the formation of large amounts of fibrous connective tissues in and around the damaged tissue. Wynn T. A. et al., Nat Med 18(7):1028-1040 (2012). Such accumulation can lead to permanent scarring, organ malfunction, and even death, as observed in many fibrotic diseases (e.g., chronic liver disease, kidney disease, idiopathic pulmonary fibrosis (IPF), and heart failure).

In some embodiments, the antagonist is an antibody, or an antigen-binding portion thereof, that specifically binds to the FAM19A5 protein (“an anti-FAM19A5 antibody or antigen-binding portion thereof”), a polynucleotide encoding the anti-FAM19A5 antibody or an antigen binding portion thereof, or a vector comprising the polynucleotide thereof. In certain embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof specifically binds to FAM19A5 protein and reduces FAM19A5 activity.

In some embodiments, the fibrosis is benign (i.e., causes no symptoms). In other embodiments, the fibrosis is associated with a pathological state, which can or cannot be reversible. In some embodiments, the fibrosis is selected from the group consisting of a hepatic fibrosis, pulmonary fibrosis, renal fibrosis, myelofibrosis, pancreatic fibrosis, skin fibrosis, cardiac fibrosis, arterial fibrosis, arthrofibrosis, breast fibrosis, muscle fibrosis, retroperitoneal Fibrosis, thyroid fibrosis, lymph node fibrosis, bladder fibrosis, systemic fibrosis, and pleural fibrosis. In one embodiment, the fibrosis is a liver fibrosis or a pulmonary fibrosis. In some embodiments, the method disclosed herein lessens, reverses, alleviates, ameliorates, inhibits, or slows down or prevents a fibrosis, a symptom associated with the fibrosis, an underlining cause of the fibrosis, or a combination thereof.

When liver is damaged, the damage causes or induces inflammation by Kupffer cells, also known as stellate macrophages and Kupffer-Browicz cells, and activation of hepatic stellate cells, which result in livery fibrosis and cirrhosis. Therefore, the present disclosure includes a method of reducing, preventing, or treating fibrosis in a subject in need thereof comprising administering to the subject a FAM19A5 antagonist.

Fibrosis can occur in various tissues or organs. Examples of such tissues or organs include, but are not limited to, the liver (hepatic fibrosis), lung (pulmonary fibrosis), kidney (renal fibrosis), bone (myelofibrosis), pancreas (pancreatic fibrosis), skin (skin fibrosis), heart (cardiac fibrosis), arteries (arterial fibrosis), joints (arthrofibrosis), breast (breast fibrosis), muscle (muscle fibrosis), retroperitoneal area (retroperitoneal fibrosis), thyroid (thyroid fibrosis), lymph node (lymph node fibrosis), bladder (bladder fibrosis), and visceral pleural of the lung (pleural fibrosis). The term “fibrosis” as used herein includes any and all types of fibrosis regardless of the cause and/or the site of the affected tissue.

In some embodiments, the fibrosis treatable by the present method includes nonalcoholic steatohepatitis (NASH). NASH is emerging as the twenty-first century's imminent public health threat. There are a lot of unmet needs in addressing the underlying complex metabolic dysfunction associated with NASH and the clinical endpoint of cirrhosis.

Fibrosis can result from or be associated with a physical injury (e.g., trauma or repetitive stress), a disease or disorder (e.g., hepatitis virus infection), exposure to a toxic agent (e.g., alcohol), or a combination thereof. Non-limiting examples of cause of fibrosis can include: scleroderma, connective tissue diseases, alcoholism, an infection, iron deposition, environmental pollutants, radiation therapy, chemotherapy, heart medications, anti-inflammatory drugs, dermatomyositis, polymyositis, systemic lupus erythematosus, osteoarthritis, rheumatoid arthritis, sarcoidosis, and non-alcoholic steatohepatitis.

In some embodiments, the methods disclosed herein can treat any grade or stage of fibrosis or fibrosis-associated disease or disorder The term “grade,” when used in the context of a fibrosis or a fibrosis-associated disease or disorder, refers to the severity of the necrosis and inflammation (“necroinflammation”) associated with the particular disease or disorder. The term “stage,” when used in the context of a fibrosis or a fibrosis-associated disease or disorder, refers to the degree of scarring, with the end stage resulting in death or organ failure (e.g., cirrhosis in the case of liver fibrosis). Goodman Z. D., J Hepatol 47(4): 598-607 (2007). The precise definition for each grade and/or stage depends on the particular disease or disorder and/or the scoring system used (e.g., Knodell System, Ishak Modification of Hepatitis Activity Index, METAVIR System, Scheuer System, and Batts-Ludwig System).

In one embodiment, the subject being treated in the method is a nonhuman animal such as a rat or a mouse. In one embodiment, the subject being treated in the method is a human.

In some embodiments, an anti-FAM19A5 antibody or antigen-binding portion thereof, or a composition thereof can be administered in combination with one or more additional agent for treating a fibrosis (e.g., pirfenidone (ESBRIET®) or nintedanib (OFEV®) for idiopathic pulmonary fibrosis). Dose and administration of the one or more additional therapeutic drugs are known in the art, e.g., as instructed by the product label of the respective drug.

In certain embodiments, the present disclosure includes a method of preventing a fibrosis in a subject in need thereof comprising administering to the subject a FAM19A5 antagonist. The fibrosis can be prevented by blocking the onset of the fibrosis formation with a prophylactic administration of the FAM19A5 antagonist to the subject.

III. Method of Diagnosing Fibrosis

Currently, the most reliable method available for diagnosing a fibrosis is through tissue biopsy. But such method is often highly invasive and has various undesirable side effects (e.g., hemorrhage at site of biopsy, pain and discomfort). Accordingly, disclosed herein are methods of diagnosing a fibrosis and/or a fibrosis-associated disease in a subject in need thereof of comprising contacting an anti-FAM19A5 antibody or antigen-binding portion thereof with a biological sample of the subject and measuring a protein level of FAM19A5 or an mRNA level encoding FAM19A5 protein in the sample. In some embodiments, the biological sample has at least 1.5 fold, at least 2 fold, at least 3 fold, at least 4 fold, at least 5 fold, at least 6 fold, at least 7 fold, at least 8 fold, at least 9 fold, at least 10 fold, at least 11 fold, at least 12 fold, at least 13 fold, at least 15 fold, at least 20 fold, at least 25 fold, or at least 30 fold increase in the protein level of FAM19A5 or an mRNA level encoding FAM19A5 protein compared to the protein level of FAM19A5 or an mRNA level encoding FAM19A5 protein in a reference sample (e.g., sample of a subject who does not have a fibrosis).

In connection with the current disclosure, Applicant has shown that subjects with fibrosis and/or a fibrosis-associated disease express higher level of FAM19A5 both in the peripheral blood and at the site of the damaged tissue. See Examples 6-10. Accordingly, the method disclosed herein can be used to diagnose fibrosis and/or a fibrosis-associated disease in a subject by measuring the subject's FAM19A5 expression level (protein and/or mRNA), where an increased expression as compared to a reference level (e.g., FAM19A5 level in a subject without fibrosis and/or a fibrosis-associated disease) would suggest that the subject has a fibrotic disease or disorder. In some embodiments, the present disclosure can be used to confirm the presence of a fibrotic disease or disorder by measuring the FAM19A5 protein level in a subject who is suspected of having a fibrotic disease or disorder In other embodiments, the disclosure provides measuring a subject's FAM19A5 protein level in combination with another assay that is used to diagnose a fibrosis and/or a fibrosis-associated disease.

In some embodiments, the protein level of FAM19A5 is measured by an immunohistochemistry, a Western blotting, a radioimmunoassay, an enzyme linked immunosorbent assay (ELISA), a radioimmunodiffusion, an immunoprecipitation assay, an Ouchterlony immunodiffusion method, a rocket immunoelectrophoresis, a tissue immunostaining method, a complement fixation assay, FACS, or a protein chip. In one embodiment, the level of an mRNA encoding the FAM19A5 protein is measured by a RT-PCR, a real time polymerase chain reaction, or a Northern blot. In some embodiments, the biological sample comprises a tissue, cell, blood, serum, plasma, saliva, cerebro spinal fluid, intravitreal fluid, or urine. Not being bound by any theory, the FAM19A5 protein increasingly expressed in fibrotic tissue can leak into the serum where the protein can be measured using any of the assays listed above. Therefore, the present disclosure provides a method of measuring the FAM19A5 protein expression in the serum of a subject who is suspected as having a fibrosis and/or a fibrosis-associated disease. This method can thus be more convenient and less intrusive than many of the currently available diagnostic methods (e.g., biopsy).

IV. FAM19A5 Antagonists Useful for the Disclosure

In some embodiments, the FAM19A5 antagonist useful for the present disclosure is an antisense oligonucleotide, siRNA, shRNA, miRNA, dsRNA, aptamer, PNA (peptide nucleic acid) that specifically targets FAM19A5, or a vector including the same. In other embodiments, the FAM19A5 antagonist is an antibody, or an antigen-binding portion thereof, that specifically binds to the FAM19A5 protein (“anti-FAM19A5 antibody”), a polynucleotide encoding the anti-FAM19A5 antibody, or a vector comprising the polynucleotide thereof.

The anti-FAM19A5 antibodies that are useful in the methods disclosed herein include monoclonal antibodies, which are characterized by particular functional features or properties. For example, the antibodies specifically bind human FAM19A5, including soluble FAM19A5 and membrane bound FAM19A5. In addition to binding specifically to soluble and/or membrane bound human FAM19A5, the antibodies described herein also (a) binds to soluble human FAM19A5 with a K_(D) of 10 nM or less; (b) binds to membrane bound human FAM19A5 with a K_(D) of 1 nM or less; or both (a) and (b).

In some embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof specifically binds to soluble human FAM19A5 or membrane-bound human with high affinity, for example, with a K_(D) of 10⁻⁷ M or less, 10⁻⁸ M or less, 10⁻⁹ M (1 nM) or less, 10⁻¹⁰ M (0.1 nM) or less, 10⁻¹¹M or less, or 10⁻¹² M (1 pM) or less, e.g., 10⁻¹² M to 10⁻¹¹ M to M, 10⁻¹⁰ M to M, or 10⁻⁹M to 10⁻⁷ M, e.g., 10⁻¹² M, 5×10⁻¹² M, 10⁻¹¹ M, 5×10⁻¹¹ M, 10⁻¹⁰ M, 5×10⁻¹⁰ M, 10⁻⁹ M, 5×10⁻⁹ M, 10⁻⁸ M, 5×10⁻⁸ M, 10⁻⁷ M, or 5×10⁻⁷ M. Standard assays to evaluate the binding ability of the antibody toward human FAM19A5 of various species are known in the art, including for example, ELISAs, Western blots, and RIAs. Suitable assays are described in detail in the Examples. The binding kinetics (e.g., binding affinity) of the antibodies also can be assessed by standard assays known in the art, such as by ELISA, BIACORE® analysis or KinExA®. Assays to evaluate the effects of the antibodies on functional properties of FAM19A5 (e.g., ligand binding) are described in further detail infra and in the Examples.

In some embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof binds to soluble human FAM19A5 with a K_(D), e.g., as determined by ELISA, of 10⁻⁷ M or less, 10⁻⁸ M (10 nM) or less, 10⁻⁹ M (1 nM) or less, 10⁻¹⁰ M or less, 10⁻¹² M to 10⁻⁷ M, 10⁻¹¹ M to 10⁻⁷ M, 10⁻¹° M to 10⁻⁷ M, 10⁻⁹ M to 10⁻⁷ M, or 10⁻⁸ M to 10⁻⁷ M. In some embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof binds to soluble FAM19A5 with a K_(D) of 10 nM or less, e.g., between 0.1 and 10 nM, between 0.1 and 5 nM, between 0.1 and 1 nM, between 0.5 and 10 nM, between 0.5 and 5 nM, between 0.5 and 1 nM, between 1 and 10 nM, between 1 and 5 nM, or between 5 and 10 nM. In some embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof specifically binds to soluble human FAM19A5 with a K_(D) of about 1 pM, 2 pM, 3 pM, 4 pM, 5 pM, 6 pM, 7 pM, 8 pM, 9 pM, 10 pM, 20 pM, 30 pM, 40 pM, 50 pM, 60 pM, 70 pM, 80 pM, 90 pM, 100 pM, 200 pM, 300 pM, 400 pM, 500 pM, 600 pM, 700 pM, 800 pM, or 900 pM, or about 1 nM, 2 nM, 3 nM, 4 nM, 5 nM, 6 nM, 7 nM, 8 nM, or 9 nM, or about 10 nM, 20 nM, 30 nM, 40 nM, 50 nM, 60 nM, 70 nM, 80 nM, or 90 nM, as determined by as determined by ELISA.

In some embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof binds to membrane-bound human with a K_(D), e.g., as determined by ELISA, of 10⁻⁷ M or less, 10⁻⁸ M (10 nM) or less, 10⁻⁹ M (1 nM) or less, 10⁻¹⁰ M or less, 10⁻¹² M to 10⁻⁷ M, 10⁻¹¹ M to 10⁻⁷ M, 10⁻¹° M to 10⁻⁷ M, 10⁻⁹ M to 10⁻⁷ M, or 10⁻⁸ M to 10⁻⁷ M. In certain embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof specifically binds to membrane-bound human FAM19A5 with a K_(D) of 10 nM or less as determined by ELISA, e.g., between 0.1 and 10 nM, between 0.1 and 5 nM, between 0.1 and 1 nM, between 0.5 and 10 nM, between 0.5 and 5 nM, between 0.5 and 1 nM, between 1 and 10 nM, between 1 and 5 nM, or between 5 and 10 nM. In some embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof binds to membrane-bound human FAM19A5 with a K_(D) of about 1 pM, 2 pM, 3 pM, 4 pM, 5 pM, 6 pM, 7 pM, 8 pM, 9 pM, 10 pM, 20 pM, 30 pM, 40 pM, 50 pM, 60 pM, 70 pM, 80 pM, 90 pM, 100 pM, 200 pM, 300 pM, 400 pM, 500 pM, 600 pM, 700 pM, 800 pM, or 900 pM, or about 1 nM, 2 nM, 3 nM, 4 nM, 5 nM, 6 nM, 7 nM, 8 nM, or 9 nM, or about 10 nM, 20 nM, 30 nM, 40 nM, 50 nM, 60 nM, 70 nM, 80 nM, or 90 nM, as determined by as determined by ELISA.

In certain embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof of useful in the methods disclosed herewith thereof cross-competes for binding to (or inhibits binding of) a human FAM19A5 epitope with an anti-FAM19A5 antibody comprising CDRs or variable regions disclosed herein.

In certain embodiments, anti-FAM19A5 antibodies or antigen binding portions thereof inhibit binding of a reference antibody comprising heavy chain CDR1, CDR2, and CDR3, and light chain CDR1, CDR2, and CDR3, (i) wherein the heavy chain CDR1, CDR2, and CDR3 of the reference antibody comprise the amino acid sequence of SEQ ID NO: 11, SEQ ID NO: 12, and SEQ ID NO: 13, respectively, and light chain CDR1, CDR2, and CDR3 of the reference antibody comprise the amino acid sequence of SEQ ID NO: 23, SEQ ID NO: 24, and SEQ ID NO: 25, respectively; (ii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 14, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 15, and the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 16, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 26, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 27, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 28; (iii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 17, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 18, and the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 19, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 29, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 30, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 31; (iv) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 20, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 21, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 22, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 32, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 33, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 34; (v) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 89, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 90, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 91, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 92, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 93, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 94; (vi) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 95, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 96, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 97, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 98, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 99, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 100; (vii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 101, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 102, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 103, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 104, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 105, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 106; (viii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 107, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 108, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 109, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 110, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 111, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 112; (ix) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 113, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 114, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 115, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 116, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 117, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 118; (x) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 119, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 120, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 121, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 122, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 123, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 124; (xi) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 125, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 126, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 127, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 128, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 129, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 130; (xii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 131, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 132, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 133, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 134, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 135, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 136; (xiii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 137, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 138, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 139, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 140, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 141, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 142; (xiv) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 143, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 144, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 145, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 146, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 147, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 148; or (xv) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 149, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 150, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 151, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 152, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 153, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 154.

In some embodiments, the reference antibody comprises (a) heavy and light chain variable region sequences comprising SEQ ID NOs: 35 and 39, respectively; (b) heavy and light chain variable region sequences comprising SEQ ID NOs: 36 and 40, respectively; (c) heavy and light chain variable region sequences comprising SEQ ID NOs: 37 and 41, respectively; (d) heavy and light chain variable region sequences comprising SEQ ID NOs: 38 and 42, respectively; (e) heavy and light chain variable region sequences comprising SEQ ID NOs: 155 and 166, respectively; (f) heavy and light chain variable region sequences comprising SEQ ID NOs: 156 and 167, respectively; (g) heavy and light chain variable region sequences comprising SEQ ID NOs: 157 and 168, respectively; (h) heavy and light chain variable region sequences comprising SEQ ID NOs: 158 and 169, respectively; (i) heavy and light chain variable region sequences comprising SEQ ID NOs: 159 and 170, respectively; (j) heavy and light chain variable region sequences comprising SEQ ID NOs: 160 and 171, respectively; (k) heavy and light chain variable region sequences comprising SEQ ID NOs: 161 and 172, respectively; (1) heavy and light chain variable region sequences comprising SEQ ID NOs: 162 and 173, respectively; (m) heavy and light chain variable region sequences comprising SEQ ID NOs: 163 and 174, respectively; (n) heavy and light chain variable region sequences comprising SEQ ID NOs: 164 and 175, respectively; or; or (o) heavy and light chain variable region sequences comprising SEQ ID NOs: 165 and 176, respectively.

In certain embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof inhibits binding of such a reference antibody to human FAM19A5 by at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% or by 100%. Competing antibodies bind to the same epitope, an overlapping epitope or to adjacent epitopes (e.g., as evidenced by steric hindrance). Whether two antibodies compete with each other for binding to a target can be determined using competition experiments known in the art such as RIA and EIA.

In certain embodiments, the anti-FAM19A5 antibody or antigen binding portions thereof bind to the same FAM19A5 epitope as a reference antibody disclosed herein comprising heavy chain CDR1, CDR2, and CDR3 and light chain CDR1, CDR2, and CDR3, (i) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 11, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 12, and the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 13, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 23, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 24, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 25; (ii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 14, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 15, and the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 16, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 26, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 27, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 28; (iii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 17, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 18, and the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 19, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 29, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 30, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 31; (iv) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 20, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 21, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 22, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 32, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 33, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 34; (v) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 89, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 90, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 91, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 92, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 93, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 94; (vi) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 95, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 96, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 97, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 98, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 99, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 100; (vii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 101, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 102, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 103, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 104, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 105, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 106; (viii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 107, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 108, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 109, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 110, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 111, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 112; (ix) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 113, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 114, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 115, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 116, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 117, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 118; (x) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 119, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 120, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 121, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 122, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 123, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 124; (xi) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 125, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 126, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 127, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 128, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 129, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 130; (xii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 131, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 132, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 133, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 134, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 135, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 136; (xiii) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 137, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 138, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 139, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 140, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 141, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 142; (xiv) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 143, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 144, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 145, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 146, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 147, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 148; or (xv) wherein the heavy chain CDR1 comprises the amino acid sequence of SEQ ID NO: 149, the heavy chain CDR2 comprises the amino acid sequence of SEQ ID NO: 150, the heavy chain CDR3 comprises the amino acid sequence of SEQ ID NO: 151, the light chain CDR1 comprises the amino acid sequence of SEQ ID NO: 152, the light chain CDR2 comprises the amino acid sequence of SEQ ID NO: 153, and the light chain CDR3 comprises the amino acid sequence of SEQ ID NO: 154.

In some embodiments, the reference antibody comprises (a) heavy and light chain variable region sequences comprising SEQ ID NOs: 35 and 39, respectively; (b) heavy and light chain variable region sequences comprising SEQ ID NOs: 36 and 40, respectively; (c) heavy and light chain variable region sequences comprising SEQ ID NOs: 37 and 41, respectively; (d) heavy and light chain variable region sequences comprising SEQ ID NOs: 38 and 42, respectively; (e) heavy and light chain variable region sequences comprising SEQ ID NOs: 155 and 166, respectively; (f) heavy and light chain variable region sequences comprising SEQ ID NOs: 156 and 167, respectively; (g) heavy and light chain variable region sequences comprising SEQ ID NOs: 157 and 168, respectively; (h) heavy and light chain variable region sequences comprising SEQ ID NOs: 158 and 169, respectively; (i) heavy and light chain variable region sequences comprising SEQ ID NOs: 159 and 170, respectively; (j) heavy and light chain variable region sequences comprising SEQ ID NOs: 160 and 171, respectively; (k) heavy and light chain variable region sequences comprising SEQ ID NOs: 161 and 172, respectively; (1) heavy and light chain variable region sequences comprising SEQ ID NOs: 162 and 173, respectively; (m) heavy and light chain variable region sequences comprising SEQ ID NOs: 163 and 174, respectively; (n) heavy and light chain variable region sequences comprising SEQ ID NOs: 164 and 175, respectively; or (o) heavy and light chain variable region sequences comprising SEQ ID NOs: 165 and 176, respectively.

Techniques for determining whether two antibodies bind to the same epitope include, e.g., epitope mapping methods, such as, x-ray analyses of crystals of antigen:antibody complexes which provides atomic resolution of the epitope and hydrogen/deuterium exchange mass spectrometry (HDX-MS), methods monitoring the binding of the antibody to antigen fragments or mutated variations of the antigen, where loss of binding due to a modification of an amino acid residue within the antigen sequence is often considered an indication of an epitope component, computational combinatorial methods for epitope mapping.

An anti-FAM19A5 antibody or antigen binding portion thereof that would be useful in the methods disclosed herewith can bind to at least one epitope of mature human FAM19A5, as determined, e.g., by binding of the antibodies to fragments of human FAM19A5. In some embodiments, anti-FAM19A5 antibodies or antigen binding portions thereof bind to a fragment located within the amino acid sequence of TLDRDSSQPRRTIARQTARC (SEQ ID NO: 6 or amino acid residues 42 to 61 of SEQ ID NO: 2), e.g., an epitope having at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acids of SEQ ID NO: 6. In some embodiments, anti-FAM19A5 antibodies or antigen binding portion thereof bind to SEQ ID NO: 6 at one or more amino acids corresponding to amino acid residues 46 to 51 (i.e., DSSQPR), e.g., amino acid residues 46, 50, and 52 (i.e., D---P-R), e.g., amino acid residues 46, 47, 48, and 50 (i.e., DSS-P) of SEQ ID NO: 2. In some embodiments, anti-FAM19A5 antibodies or antigen binding portions thereof bind to a fragment located within the amino acid sequence of CDMLPCLEGEGCDLLINRSG (SEQ ID NO: 9 or amino acids 90 to 109 of SEQ ID NO: 2), e.g., an epitope having at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acids of SEQ ID NO: 9. In certain embodiments, anti-FAM19A5 antibodies or antigen binding portion thereof bind to SEQ ID NO: 9 at one or more amino acids residues 99 to 107 (i.e., EGCDLLINR), e.g., amino acid residues 102, 103, 105, and 107 (i.e., DL-I-R), e.g., amino acid residues 99, 100, 102, 103, 105, and 107 (i.e., EG-DL-I-R), e.g., amino acid residues 99, 100, and 107 (i.e., EG------R) of SEQ ID NO: 4.

In some embodiments, the at least one epitope has the amino acid sequence that is at least 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to SEQ ID NO: 6. In some embodiments, the at least one epitope has the amino acid sequence that is at least 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to SEQ ID NO: 9.

In some embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof binds to a human FAM19A5 epitope only, which is SEQ ID NO: 5, 6, 7, 8, 9, or 10, or a fragment located within the amino acid sequence of SEQ ID NO: 5, 6, 7, 8, 9, or 10, e.g., an epitope having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acids of SEQ ID NO: 5, 6, 7, 8, 9, or 10.

In some embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof of the present disclosure binds to SEQ ID NO: 6 or a fragment thereof in its native conformation (i.e., un-denatured). In some embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof of the present disclosure binds to SEQ ID NO: 9 or a fragment thereof in its native conformation (i.e., un-denatured). In some embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof binds to both glycosylated and unglycosylated human FAM19A5.

In some embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof further binds to one or more additional FAM19A5 epitopes. Therefore, certain anti-FAM19A5 antibodies or antigen binding portions thereof bind to an epitope of SEQ ID NO: 6 and an additional epitope or an epitope of SEQ ID NO: 9 and an additional epitope. Other anti-FAM19A5 antibodies or antigen binding portions thereof can bind to an epitope of SEQ ID NO: 5, SEQ ID NO: 9, and an additional epitope. In some embodiments, anti-FAM19A5 antibodies or antigen binding portions thereof bind to an epitope of SEQ ID NO: 6, an epitope of SEQ ID NO: 10, and an additional epitope. In some embodiments, the one or more additional FAM19A5 epitopes are selected from QLAAGTCEIVTLDR (SEQ ID NO: 5, epitope F1), TLDRDSSQPRRTIARQTARC (SEQ ID NO: 6, epitope F2), TARCACRKGQIAGTTRARPA (SEQ ID NO: 7, epitope F3), ARPACVDARIIKTKQWCDML (SEQ ID NO: 8, epitope F4), CDMLPCLEGEGCDLLINRSG (SEQ ID NO: 9, epitope F5), or NRSGWTCTQPGGRIKTTTVS (SEQ ID NO: 10, epitope F6), or a fragment located within the amino acid sequence of SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, or any combination thereof. A fragment located within the amino acid sequence of SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, or SEQ ID NO: 10, includes a fragment having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acids of any of SEQ ID NO: 5, SEQ ID NO: 6, and SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, or SEQ ID NO: 10. In some embodiments, the one or more additional FAM19A5 epitopes are selected from SEQ ID NO: 5, 6, 7, 8, 9, or 10, or a fragment located within the amino acid sequence of SEQ ID NO: 5, 6, 7, 8, 9, or 10, e.g., a fragment having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acids of SEQ ID NO: 5, 6, 7, 8, 9, or 10, or any combination thereof. In some embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof of the disclosure binds to any of the one or more additional epitopes in their native conformation (i.e., un-denatured). In some embodiments, the anti-FAM19A5 antibody or antigen binding portion thereof binds to both glycosylated and unglycosylated of the one or more additional FAM19A5 epitopes.

In some embodiments, anti-FAM19A5 antibodies or antigen binding portions thereof bind to at least one FAM19A5 epitope identified as EP2, EP4, and/or EP8, wherein EP2 comprises, consists essentially of, or consists of the amino acids DSSQP (SEQ ID NO: 66), wherein EP4 comprises, consists essentially of, or consists of the amino acids ARCACRK (SEQ ID NO: 68), and wherein EP8 comprises, consists essentially of, or consists of the amino acids TCTQPGGR (SEQ ID NO: 72). In some embodiments, the at least one epitope has the amino acid sequence that is at least 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to EP2, EP4, or EP8. In some embodiments, anti-FAM19A5 antibodies or antigen binding portion thereof only bind to EP2. In some embodiments, anti-FAM19A5 antibodies or antigen binding portion thereof bind to EP4 and EP8.

In some embodiments, the anti-FAM19A5 antibody, or antigen binding portion thereof, binds to at least one FAM19A5 epitope identified as EP6, EP7, or EP8, wherein EP6 comprises the amino acids KTKQWCDML (SEQ ID NO: 70), wherein EP7 comprises the amino acids GCDLLINR (SEQ ID NO: 71), and wherein EP8 comprises the amino acids TCTQPGGR (SEQ ID NO: 72). In some embodiments, the at least one epitope has the amino acid sequence that is at least 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to EP6, EP7, or EP8. In some embodiments, the anti-FAM19A5 antibody, or antigen binding portion thereof, only binds to EP6, EP7, or EP8. In some embodiments, the anti-FAM19A5 antibody, or antigen binding portion thereof, binds to EP6, EP7, and EP8. In some embodiments, the anti-FAM19A5 antibody, or antigen binding portion thereof, binds to EP7 and EP8. In some embodiments, the anti-FAM19A5 antibody, or antigen binding portion thereof, binds to EP7.

In some embodiments, anti-FAM19A5 antibodies or antigen binding portion thereof bind to one or more FAM19A5 epitopes selected from the group consisting of SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68, SEQ ID NO: 69, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 72, and any combinations thereof.

In certain embodiments, provided herein is an antibody or antigen binding portion thereof that binds to FAM19A5 (e.g., human FAM19A5) with a 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or higher affinity than to another protein in the FAM19A family as measured by, e.g., a immunoassay (e.g., ELISA), surface plasmon resonance, or kinetic exclusion assay. In a specific embodiment, provided herein is an antibody or antigen binding portion thereof that binds to FAM19A5 (e.g., human FAM19A5) with no cross reactivity with another protein in the FAM19A family as measured by, e.g., an immunoassay.

In certain embodiments, the anti-FAM19A5 antibodies are not native antibodies or are not naturally-occurring antibodies. For example, the anti-FAM19A5 antibodies have post-translational modifications that are different from those of antibodies that are naturally-occurring, such as by having more, less or a different type of post-translational modification.

V. Exemplary Anti-FAM19A5 Antibodies

Particular antibodies that can be used in the methods disclosed herein are antibodies, e.g., monoclonal antibodies, having the CDR and/or variable region sequences disclosed herein, as well as antibodies having at least 80% identity (e.g., at least 85%, at least 90%, at least 95%, or at least 99% identity) to their variable region or CDR sequences. The VH and VL amino acid sequences of different anti-FAM19A5 antibodies of the present disclosure are provided in Tables 4 and 5, respectively.

TABLE 2 Variable heavy chain CDR amino acid sequences (according to Kabat system) Antibody VH-CDR1 VH-CDR2 VH-CDR3 Anti-FAM19A5 SHGMF EITNDGSGTNYGSAVKG STYECPGGFSCWGDTGQI (″2-13″) (SEQ ID NO: 11) (SEQ ID NO: 12) DA (SEQ ID NO: 13) Anti-FAM19A5 SFNMF QISSSGSSTNYAPAVRG SSYDCPYGHCSSGVDSAG (″3-2″) (SEQ ID NO: 14) (SEQ ID NO: 15) EIDA (SEQ ID NO: 16) Anti-FAM19A5 SYQMG VINKSGSDTS GSASYITAATIDA (″1-65″) (SEQ ID NO: 17) (SEQ ID NO: 18) (SEQ ID NO: 19) Anti-FAM19A5 GFDFSDYG IRSDGSNP AKDGNGYCALDAYRSGGY (″1-28″) (SEQ ID NO: 20) (SEQ ID NO: 21) SCGVYPGSIDA (SEQ ID NO: 22) Anti-FAM19A5 TYAVT YINWRGGTSYANWAKG DASSGAAFGSYGMDP (″P2-C12″) (SEQ ID NO: 89) (SEQ ID NO: 90) (SEQ ID NO: 91) Anti-FAM19A5 SSNWWS EIYHGGTTNYNPSLKG WQLVGGLDV (″13B4″) (SEQ ID NO: 95) (SEQ ID NO: 96) (SEQ ID NO: 97) Anti-FAM19A5 GYSWT EISHFGSANYNPSLKS ALRGTYSRFYYGMDV (″13F7″) (SEQ ID NO: 101) (SEQ ID NO: 102) (SEQ ID NO: 103) Anti-FAM19A5 SYYWS YIYPSGSTNYNPSLKS VNPFGYYYAMDV (″15A9″) (SEQ ID NO: 107) (SEQ ID NO: 108) (SEQ ID NO: 109) Anti-FAM19A5 SDYMS IIYPSTITYYASWAKG GSNWSSGMNL (″P1-A03″) (SEQ ID NO: 113) (SEQ ID NO: 114) (SEQ ID NO: 115) Anti-FAM19A5 TYYMS IVYPSGTTYYANWAKG GDSFGYGL (″P1-A08″) (SEQ ID NO: 119) (SEQ ID NO: 120) (SEQ ID NO: 121) Anti-FAM19A5 NYYMG IIYASGSTYYASWAKG IDIGVGDYGWAYDRLDL (″P1-F02″) (SEQ ID NO: 125) (SEQ ID NO: 126) (SEQ ID NO: 127) Anti-FAM19A5 GYYMS IIYPSGSTDYASWAKG VAGYVGYGYETFEDI (″P2-A01″) (SEQ ID NO: 131) (SEQ ID NO: 132) (SEQ ID NO: 133) Anti-FAM19A5 NYDMS FMDTDGSAYYATWAKG RGSSYYGGIDI (″P2-A03″) (SEQ ID NO: 137) (SEQ ID NO: 138) (SEQ ID NO: 139) Anti-FAM19A5 SYYMN IIYPSGTTYYAGWAKG TVSGYFDI (″P2-F07″) (SEQ ID NO: 143) (SEQ ID NO: 144) (SEQ ID NO: 145) Anti-FAM19A5 SYGVS YIANNYNPHYASWAKG DNYGMDP (″P2-F11″) (SEQ ID NO: 149) (SEQ ID NO: 150) (SEQ ID NO: 151)

TABLE 3 Variable light chain CDR amino acid sequences (according to Kabat system) Antibody VL-CDR1 VL-CDR2 VL-CDR3 Anti-FAM19A5 SGGSYSYG WDDERPS GTEDISGTAGV (″2-13″) (SEQ ID NO: 23) (SEQ ID NO: 24) (SEQ ID NO: 25) Anti-FAM19A5 SGGGSYAGSYYYG ESNKRPS GSWDSSNGGI (″3-2″) (SEQ ID NO: 26) (SEQ ID NO: 27) (SEQ ID NO: 28) Anti-FAM19A5 SGGGSSGYGYG WNDKRPS GNDDYSSDSGYVGV (″1-65″) (SEQ ID NO: 29) (SEQ ID NO: 30) (SEQ ID NO: 31) Anti-FAM19A5 GYGYG QND GSEDSSTLAGI (″1-28″) (SEQ ID NO: 32) (SEQ ID NO: 33) (SEQ ID NO: 34) Anti-FAM19A5 QASQSISSYLS EASKLAS QQGYSSTNVWNA (″P2-C12″) (SEQ ID NO: 92) (SEQ ID NO: 93) (SEQ ID NO: 94) Anti-FAM19A5 SGDKLGNVYAS QDNKRPS QAWDSSTAV (″13B4″) (SEQ ID NO: 98) (SEQ ID NO: 99) (SEQ ID NO: 100) Anti-FAM19A5 RSSQSLLHSNGYNYLD LGSNRAS MQARQTPLT (″13F7″) (SEQ ID NO: 104) (SEQ ID NO: 105) (SEQ ID NO: 106) Anti-FAM19A5 RASQSISTSLN GASTLQS QESASIPRT (″15A9″) (SEQ ID NO: 110) (SEQ ID NO: 111) (SEQ ID NO: 112) Anti-FAM19A5 LASEDIYSGIS GASNLES LGGYSYSSTGLT (″P1-A03″) (SEQ ID NO: 116) (SEQ ID NO: 117) (SEQ ID NO: 118) Anti-FAM19A5 TADTLSRSYAS RDTSRPS ATSDGSGSNYQYV (″P1-A08″) (SEQ ID NO: 122) (SEQ ID NO: 123) (SEQ ID NO: 124) Anti-FAM19A5 LASEDIYSGIS GASNLES LGGYSYSSIT (″P1-F02″) (SEQ ID NO: 128) (SEQ ID NO: 129) (SEQ ID NO: 130) Anti-FAM19A5 LASEDIYSGIS GASNLES LGGVTYSSTGTHLT (″P2-A01″) (SEQ ID NO: 134) (SEQ ID NO: 135) (SEQ ID NO: 136) Anti-FAM19A5 QASQSIGGNLA RASTLAS QSPAYDPAAYVGNA (″P2-A03″) (SEQ ID NO: 140) (SEQ ID NO: 141) (SEQ ID NO: 142) Anti-FAM19A5 LASEDIYSALA GTSNLES QGYSSYPLT (″P2-F07″) (SEQ ID NO: 146) (SEQ ID NO: 147) (SEQ ID NO: 148) Anti-FAM19A5 QASQSVYNNKNLA AASTLAS QGEFSCSSADCNA (″P2-F11″) (SEQ ID NO: 152) (SEQ ID NO: 153) (SEQ ID NO: 154)

TABLE 4 Variable heavy chain amino acid sequence Antibody VH Amino Acid Sequence (SEQ ID NO) Anti-FAM19A5 AVTLDESGGGLQTPGGALSLVCKASGFTFSSHGMFWVRQTPGKGLEYVAEITNDGSGTNY (″2-13″) GSAVKGRATISRDNGQSTVRLQLNNLRAEDTGTYFCARSTYECPGGFSCWGDTGQIDAWG HGTEVIVSS (SEQ ID NO: 35) Anti-FAM19A5 AVTLDESGGGLQTPGGALSLVCKASGFTFSSFNMFWVRQAPGKGLEYVAQISSSGSSTNY (″3-2″) APAVRGRATISRDNGQSTVRLQLNNPGAEDTGTYYCAKSSYDCPYGHCSSGVDSAGEIDA WGHGTEVIVSS (SEQ ID NO: 36) Anti-FAM19A5 AVTLDESGGGLQTPGGALSLVCKASGFTFSSYQMGWVRQAPGKGLEWVGVINKSGSDTSY (″1-65″) GSAVKGRATISRDNGQSTVRLQLNNLRAEDTGTYFCAKGSASYITAATIDAWGHGTEVIV SS (SEQ ID NO: 37) Anti-FAM19A5 AVTLDESGGGLQTPGGALSLVCKASGFDFSDYGMGWVRQAPGKGLEWVAAIRSDGSNPSY (″1-28″) GSAVKGRATISKDNGRSTVRLQLNNLRAEDTATYYCAKDGNGYCALDAYRSGGYSCGVYP GSIDAWGHGTEVIVSS (SEQ ID NO: 38) Anti-FAM19A5 QSLEESGGRLVTPGTPLTLTCTVSGFSLSTYAVTWVRQAPGKGLEWIGYINWRGGTSYAN (″P2-C12″) WAKGRFTISKTSSTTVDLKMTSPTTEDTATYFCARDASSGAAFGSYGMDPWGPGTLVTVS S (SEQ ID NO: 155) Anti-FAM19A5 QVQLQESGPGLVKPSGTLSLNCAVSGGSISSSNWWSWVRQPPGKGLEWIGEIYHGGTTNY (″13B4″) NPSLKGRVTMSVDKTKNQFSLRLSSVTAVDTAVYYCARWQLVGGLDVWGQGTTVTVSS (SEQ ID NO: 156) Anti-FAM19A5 QVQLQEWGAGLLKPSETLSLTCAINAESFNGYSWTWIRQTPGKGLEWIGEISHFGSANYN (″13F7″) PSLKSRATISADKSKNQFSLKLTSVTAVDTAVYYCARALRGTYSRFYYGMDVWGQGTTVT VSS (SEQ ID NO: 157) Anti-FAM19A5 QVQLQESGPGLVKPSETLSLTCTVSGGSISSYYWSWIRQPPGKGLEWIGYIYPSGSTNYN (″15A9″) PSLKSRVTISVDTSKNQFSLNLKSVTAVDTAVYYCARVNPFGYYYAMDVWGQGTTVTVSS (SEQ ID NO: 158) Anti-FAM19A5 QSVEESGGRLVTPGTPLTLTCTVSGFSLSSDYMSWVRQAPGEGLEWIGIIYPSTTTYYAS (″P1-A03″) WAKGRFTISKTSSTTVELKMTSLTTEDTATYFCARGSNWSSGMNLWGPGTLVTVSS (SEQ ID NO: 159) Anti-FAM19A5 QSLEESGGRLVTPGTPLTLTCTASGFSLSTYYMSWVRQAPGKGLEWIGIVYPSGTTYYAN (″P1-A08″) WAKGRFTISTASTTVDLMITSPTTEDTATYFCARGDSFGYGLWGPGTLVTVSS (SEQ ID NO: 160) Anti-FAM19A5 QSLEESGGRLVTPGTPLTLTCTASGFSLSNYYMGWVRQAPGEGLEWIGIIYASGSTYYAS (″P1-F02″) PWAKGRFTISKTSTTVDLKMTSLTTEDTATYFCARIDIGVGDYGWAYDRLDLWGQGTLVTV SS (SEQ ID NO: 161) Anti-FAM19A5 QEQLVESGGRLVTPGTPLTLSCTASGFFLSGYYMSWVRQAPGKGLEWIGIIYPSGSTDYA (″P2-A01″) SWAKGRFTISKTSTTVDLKITTPTTEDTATYFCARVAGYVGYGYETFFDIWGPGTLVTVS L (SEQ ID NO: 162) Anti-FAM19A5 QSVEESGGRLVTPGTPLTLTCTVSGFSLNNYDMSWVRQAPGKGLEYIGFMDTDGSAYYAT (″P2-A03″) WAKGRFTISRTSTTVDLKMTSPTTEDTATYFCARRGSSYYGGIDIWGPGTPVTVSL (SEQ ID NO: 163) Anti-FAM19A5 QSLEESGGRLVTPGTPLTLTCTASGFSLSSYYMNWVRQAPGKGLEWIGIIYPSGTTYYAG (″P2-F07″) WAKGRFTISKTSTTVDLKITSPTSEDTATYFCARTVSGYFDIWGPGTLVTVSL (SEQ ID NO: 164) Anti-FAM19A5 QEQLVESGGRLVTPGTTLTLTCTVSGFSLSSYGVSWVRQAPGKGLEWIGYIANNYNPHYA (″P2-F11″) SWAKGRFTISKTSSTTVDLKMTSLTTEDTATYFCARDNYGMDPWGPGTLVTVSS (SEQ ID NO: 165)

TABLE 5 Variable light chain amino acid sequence Antibody VL Amino Acid Sequence (SEQ ID NO) Anti-FAM19A5 ALTQPSSVSANPGETVKITCSGGSYSYGWFQQKSPGSALVTVIYWDDERPSDIPSRFSGA (″2-13″) LSGSTNTLTITGVQADDEAVYFCGTEDISGTAGVFGAGTTLTVL (SEQ ID NO: 39) Anti-FAM19A5 ALTQPSSVSANPGETVKITCSGGGSYAGSYYYGWYQQKAPGSAPVTLIYESNKRPSDIPS (″3-2″) RFSGSTSGSTATLTITGVQADDEAIYYCGSWDSSNGGIFGAGTTLTVL (SEQ ID NO: 40) Anti-FAM19A5 ALTQPSSVSANPGETVKITCSGGGSSGYGYGWYQQKSPSSAPLTVIYWNDKRPSDIPSRF (″1-65″) SGSKSGSTHTLTITGVQAEDEAVYFCGNDDYSSDSGYVGVFGAGTTLTVL (SEQ ID NO: 41) Anti-FAM19A5 ALTQPSSVSANLEGTVEITCSGSGYGYGWYQQKSPGSAPVTVIYQNDKRPSDIPSRFSGS (″1-28″) KSGSTGTLTITGVQVEDEAVYYCGSEDSSTLAGIFGAGTTLTVL (SEQ ID NO: 42) Anti-FAM19A5 ELDMTQTPSSVSAAVGGTVTIKCQASQSISSYLSWYQQKPGQPPKLLIYEASKLASGVPS (″P2-C12″) RFSGSGYGTEFTLTISDLECADAATYYCQQGYSSTNVWNAFGGGTNVEIK (SEQ ID NO: 166) Anti-FAM19A5 SYELTQPLSVSVSPGQTASITcsGDKLGNVYASWYQQKPGQSPTLVIYQDNKRPSGIPER (″13B4″) FSGSNSGKTATLTISGTQALDEADYYCQAWDSSTAVFGGGTKLTVL (SEQ ID NO: 167) Anti-FAM19A5 DIVMTQTPLSLPVAPGEPASISCRSSQSLLHSNGYNYLDWYVQKPGQPPQLLIYLGSNRA (″13F7″) SGVPDRFSGSGSGTDFTLKISRVEAEDVGVYYCMQARQTPLTFGGGTKVEIK (SEQ ID NO: 168) Anti-FAM19A5 DIQMTQSPSSLSASVGDRITISCRASQSISTSLNWYQQTPGKAPRLLIYGASTLQSGVPS (″15A9″) RFSGGGSGTDFSLTITSLQPEDFATYYCQESASIPRTFGQGTKLDIK (SEQ ID NO: 169) Anti-FAM19A5 ELVMTQTPPSLSASVGETVRIRCLASEDIYSGISWYQQKPEKPPTLLISGASNLESGVPP (″P1-A03″) RFSGSGSGTDYTLTIGGVQAEDAATYYCLGGYSYSSTGLTFGAGTNVEIK (SEQ ID NO: 170) Anti-FAM19A5 ELVLTQSPSVQVNLGQTVSLTCTADTLSRSYASWYQQKPGQAPVLLIYRDTSRPSGVPDR (″P1-A08″) FSGSSSGNTATLTISGAQAGDEADYYCATSDGSGSNYQYVFGGGTQLTVT (SEQ ID NO: 171) Anti-FAM19A5 ELDMTQTPPSLSASVGETVRIRCLASEDIYSGISWYQQKPGKPPTLLIYGASNLESGVPP (″P1-F02″) RFSGSGSGTDYTLTIGGVQAEDAATYYCLGGYSYSSITFGAGTNVEIK (SEQ ID NO: 172) Anti-FAM19A5 ELVMTQTPPSLSASVGETVRIRCLASEDIYSGISWYQQKPGKPPTLLIYGASNLESGVPP (″P2-A01″) RFSGSGSGSDYTLTIGGVQAEDAATYYCLGGVTYSSTGTHLTFGAGTNVEIK (SEQ ID NO: 173) Anti-FAM19A5 ELDLTQTPASVSEPVGGTVTIKCQASQSIGGNLAWYQQKPGQPPKLLIYRASTLASGVPS (″P2-A03″) RFKGSGSGTDFTLTISDLECADAATYYCQSPAYDPAAYVGNAFGGGTELEIL (SEQ ID NO: 174) Anti-FAM19A5 ELDLTQTPPSLSASVGGTVTINCLASEDIYSALAWYQQKPGKPPTLLISGTSNLESGVPP (″P2-F07″) RFSGSGSGTDYTLTIGGVQAEDAATYFCQGYSSYPLTFGAGTNVEIK (SEQ ID NO: 175) Anti-FAM19A5 ELDLTQTPSSVSAAVGGTVTINCQASQSVYNNKNLAWYQQKPGQPPKLLIYAASTLASGV (″P2-F11″) SSRFKGSGSGTQFTLTISDVQCDDAATYYCQGEFSCSSADCNAFGGGTELEIL (SEQ ID NO: 176)

Accordingly, provided herein is an isolated anti-FAM19A5 antibody, or an antigen-binding portion thereof, comprising heavy and light chain variable regions, wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NOs: 35-38 or 155-165. In other embodiments, the isolated anti-FAM19A5 antibody, or an antigen binding portion thereof, comprises the CDRs of the heavy chain variable region selected from the group consisting of SEQ ID NOs: 35-38 or 155-165.

Also provided is an isolated anti-FAM19A5 antibody, or an antigen-binding portion thereof, comprising heavy and light chain variable regions, wherein the light chain variable region comprises the amino acid sequence of SEQ ID NOs: 39-42 or 166-176. In other embodiments, the isolated anti-FAM19A5 antibody, or an antigen binding portion thereof, comprises the CDRs of the light chain variable region selected from the group consisting of SEQ ID NOs: 39-42 or 166-176.

In certain embodiments, the isolated anti-FAM19A5 antibody, or an antigen binding portion thereof, comprises the CDRs of the heavy chain variable region selected from the group consisting of SEQ ID NOs: 35-38 or 155-165 and the CDRs of the light chain variable region selected from the group consisting of SEQ ID NOs: 39-42 or 166-176.

Also provided is an isolated anti-FAM19A5 antibody, or an antigen-binding portion thereof, comprising heavy and light chain variable regions, (i) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 35 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 39; (ii) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 36 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 40; (iii) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 37 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 41; (iv) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 38 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 42; (v) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 155 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 166; (vi) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 156 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 167; (vii) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 157 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 168; (viii) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 158 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 169; (ix) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 159 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 170; (x) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 160 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 171; (xi) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 161 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 172; (xii) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 162 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 173; (xiii) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 163 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 174; (xiv) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 164 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 175; and (xv) wherein the heavy chain variable region comprises the amino acid sequence of SEQ ID NO: 165 and wherein the light chain variable region comprises the amino acid sequence of SEQ ID NO: 176.

Provided herein is an isolated anti-FAM19A5 antibody, or an antigen-binding portion thereof, comprising a heavy chain variable region and a light chain variable region, wherein the heavy chain variable region comprises an amino acid sequence which is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to the amino acid sequence set forth as SEQ ID NOs: 35-38 or 155-165.

Also provided herein is an isolated anti-FAM19A5 antibody, or an antigen-binding portion thereof, comprising a heavy chain variable region and a light chain variable region, wherein the light chain variable region comprises an amino acid sequence which is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to the amino acid sequence set forth as SEQ ID NOs: 39-42 or 166-176.

Also provided is an isolated anti-FAM19A5 antibody, or an antigen-binding portion thereof, comprising heavy and light chain variable regions, wherein the heavy chain variable region comprises an amino acid sequence which is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to the amino acid sequence set forth as SEQ ID NOs: 35-38 or 155-165, and wherein the light chain variable region comprises an amino acid sequence which is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to the amino acid sequence set forth as SEQ ID NOs: 39-42 or 166-176.

In some embodiments, the disclosure provides an isolated anti-FAM19A5 antibody, or an antigen-binding portion thereof, comprising:

(a) heavy and light chain variable region sequences comprising SEQ ID NOs: 35 and 39, respectively; (b) heavy and light chain variable region sequences comprising SEQ ID NOs: 36 and 40, respectively; (c) heavy and light chain variable region sequences comprising SEQ ID NOs: 37 and 41, respectively; (d) heavy and light chain variable region sequences comprising SEQ ID NOs: 38 and 42, respectively; (e) heavy and light chain variable region sequences comprising SEQ ID NOs: 155 and 166, respectively; (f) heavy and light chain variable region sequences comprising SEQ ID NOs: 156 and 167, respectively; (g) heavy and light chain variable region sequences comprising SEQ ID NOs: 157 and 168, respectively; (h) heavy and light chain variable region sequences comprising SEQ ID NOs: 158 and 169, respectively; (i) heavy and light chain variable region sequences comprising SEQ ID NOs: 159 and 170, respectively; (j) heavy and light chain variable region sequences comprising SEQ ID NOs: 160 and 171, respectively; (k) heavy and light chain variable region sequences comprising SEQ ID NOs: 161 and 172, respectively; (1) heavy and light chain variable region sequences comprising SEQ ID NOs: 162 and 173, respectively; (m) heavy and light chain variable region sequences comprising SEQ ID NOs: 163 and 174, respectively; (n) heavy and light chain variable region sequences comprising SEQ ID NOs: 164 and 175, respectively; or (o) heavy and light chain variable region sequences comprising SEQ ID NOs: 165 and 176, respectively.

In certain embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof of the present disclosure comprises (i) the heavy chain CDR1, CDR2 and CDR3 of 2-13, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of 2-13, or any combinations thereof; (ii) the heavy chain CDR1, CDR2 and CDR3 of 3-2, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of 3-2, or any combinations thereof; (iii) the heavy chain CDR1, CDR2 and CDR3 of 1-65, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of 1-65, or any combinations thereof; (iv) the heavy chain CDR1, CDR2 and CDR3 of 1-28, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of 1-28, or any combinations thereof; (v) the heavy chain CDR1, CDR2, and CDR3 of P2-C12, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of P2-C12, or any combinations thereof; (vi) the heavy chain CDR1, CDR2, and CDR3 of 13B4, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of 13B4, or any combinations thereof; (vii) the heavy chain CDR1, CDR2, and CDR3 of 13F7, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of 13F7, or any combinations thereof; (viii) the heavy chain CDR1, CDR2, and CDR3 of 15A9, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of 15A9, or any combinations thereof; (ix) the heavy chain CDR1, CDR2, and CDR3 of P1-A03, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of P1-A03, or any combinations thereof; (x) the heavy chain CDR1, CDR2, and CDR3 of P1-A08, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of P1-A08, or any combinations thereof; (xi) the heavy chain CDR1, CDR2, and CDR3 of P1-F02, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of P1-F02, or any combinations thereof; (xii) the heavy chain CDR1, CDR2, and CDR3 of P2-A01, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of P2-A01, or any combinations thereof; (xiii) the heavy chain CDR1, CDR2, and CDR3 of P2-A03, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of P2-A03, or any combinations thereof; (xiv) the heavy chain CDR1, CDR2, and CDR3 of P2-F07, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of P2-F07, or any combinations thereof; or (xv) the heavy chain CDR1, CDR2, and CDR3 of P2-F11, or combinations thereof, and/or the light chain CDR1, CDR2, and CDR3 of F2-F11, or any combinations thereof. The amino acid sequences of the VH CDR1, CDR2, and CDR3 for the different anti-FAM19A5 antibodies disclosed herein are provided in Table 2. The amino acid sequences of the VL CDR1, CDR2, and CDR3 for the different anti-FAM19A5 antibodies disclosed herein are provided in Table 3.

The amino acid sequences of the VH CDR1, CDR2, and CDR3 for 2-13 are set forth in SEQ ID NOs: 11, 12, and 13, respectively. The amino acid sequences of the VL CDR1, CDR2s and CDR3 for 2-13 are set forth in SEQ ID NOs: 23, 24, and 25, respectively. The amino acid sequences of the VH CDR1, CDR2, and CDR3 for 3-2 are set forth in SEQ ID NOs: 14, 15, and 16, respectively. The amino acid sequences of the VL CDR1, CDR2s and CDR3 for 3-2 are set forth in SEQ ID NOs: 26, 27, and 28, respectively. The amino acid sequences of the VH CDR1, CDR2, and CDR3 for 1-65 are set forth in SEQ ID NOs: 17, 18, and 19, respectively. The amino acid sequences of the VL CDR1, CDR2s and CDR3 for 1-65 are set forth in SEQ ID NOs: 29, 30, and 31, respectively. The amino acid sequences of the VH CDR1, CDR2, and CDR3 for 1-28 are set forth in SEQ ID NOs: 20, 21, and 22, respectively. The amino acid sequences of the VL CDR1, CDR2s and CDR3 for 1-28 are set forth in SEQ ID NOs: 32, 33, and 34, respectively.

In some embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof of the disclosure, which specifically binds to human FAM19A5, comprises:

(a) a VH CDR1 comprising the amino acid sequence of SEQ ID NO: 11; and/or (b) a VH CDR2 comprising the amino acid sequence of SEQ ID NO: 12; and/or (c) a VH CDR3 comprising the amino acid sequence of SEQ ID NO: 13.

In specific embodiments, the antibody or antigen-binding portion thereof comprises one, two, or all three of the VH CDRs above.

In some embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof, which specifically binds to human FAM19A5, comprises:

(a) a VL CDR1 comprising the amino acid sequence of SEQ ID NO: 23; and/or (b) a VL CDR2 comprising the amino acid sequence of SEQ ID NO: 24; and/or (c) a VL CDR3 comprising the amino acid sequence of SEQ ID NO: 25.

In specific embodiments, the antibody or antigen-binding portion thereof comprises one, two, or all three of the VL CDRs above.

In some embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof, which specifically binds to human FAM19A5, comprise:

(a) a VH CDR1 comprising the amino acid sequence of SEQ ID NO: 11; (b) a VH CDR2 comprising the amino acid sequence of SEQ ID NO: 12; (c) a VH CDR3 comprising the amino acid sequence of SEQ ID NO: 13; (d) a VL CDR1 comprising the amino acid sequence of SEQ ID NO: 23; (e) a VL CDR2 comprising the amino acid sequence of SEQ ID NO: 24; and/or (f) a VL CDR3 comprising the amino acid sequence of SEQ ID NO: 25.

In some embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof of the disclosure, which specifically binds to human FAM19A5, comprises:

(a) a VH CDR1 comprising the amino acid sequence of SEQ ID NO: 14; and/or (b) a VH CDR2 comprising the amino acid sequence of SEQ ID NO: 15; and/or (c) a VH CDR3 comprising the amino acid sequence of SEQ ID NO: 16.

In specific embodiments, the antibody or antigen-binding portion thereof comprises one, two, or all three of the VH CDRs above.

In some embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof, which specifically binds to human FAM19A5, comprises:

(a) a VL CDR1 comprising the amino acid sequence of SEQ ID NO: 26; and/or (b) a VL CDR2 comprising the amino acid sequence of SEQ ID NO: 27; and/or (c) a VL CDR3 comprising the amino acid sequence of SEQ ID NO: 28.

In specific embodiments, the antibody or antigen-binding portion thereof comprises one, two, or all three of the VL CDRs above.

In some embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof, which specifically binds to human FAM19A5, comprise:

(a) a VH CDR1 comprising the amino acid sequence of SEQ ID NO: 14; (b) a VH CDR2 comprising the amino acid sequence of SEQ ID NO: 15; (c) a VH CDR3 comprising the amino acid sequence of SEQ ID NO: 16; (d) a VL CDR1 comprising the amino acid sequence of SEQ ID NO: 26; (e) a VL CDR2 comprising the amino acid sequence of SEQ ID NO: 27; and/or (f) a VL CDR3 comprising the amino acid sequence of SEQ ID NO: 28.

In some embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof of the disclosure, which specifically binds to human FAM19A5, comprises:

(a) a VH CDR1 comprising the amino acid sequence of SEQ ID NO: 17; and/or (b) a VH CDR2 comprising the amino acid sequence of SEQ ID NO: 18; and/or (c) a VH CDR3 comprising the amino acid sequence of SEQ ID NO: 19.

In specific embodiments, the antibody or antigen-binding portion thereof comprises one, two, or all three of the VH CDRs above.

In some embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof, which specifically binds to human FAM19A5, comprises:

(a) a VL CDR1 comprising the amino acid sequence of SEQ ID NO: 29; and/or (b) a VL CDR2 comprising the amino acid sequence of SEQ ID NO: 30; and/or (c) a VL CDR3 comprising the amino acid sequence of SEQ ID NO: 31.

In specific embodiments, the antibody or antigen-binding portion thereof comprises one, two, or all three of the VL CDRs above.

In some embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof, which specifically binds to human FAM19A5, comprise:

(a) a VH CDR1 comprising the amino acid sequence of SEQ ID NO: 17; (b) a VH CDR2 comprising the amino acid sequence of SEQ ID NO: 18; (c) a VH CDR3 comprising the amino acid sequence of SEQ ID NO: 19; (d) a VL CDR1 comprising the amino acid sequence of SEQ ID NO: 29; (e) a VL CDR2 comprising the amino acid sequence of SEQ ID NO: 30; and/or (f) a VL CDR3 comprising the amino acid sequence of SEQ ID NO: 31.

In some embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof of the disclosure, which specifically binds to human FAM19A5, comprises:

(a) a VH CDR1 comprising the amino acid sequence of SEQ ID NO: 20; and/or (b) a VH CDR2 comprising the amino acid sequence of SEQ ID NO: 21; and/or (c) a VH CDR3 comprising the amino acid sequence of SEQ ID NO: 22.

In specific embodiments, the antibody or antigen-binding portion thereof comprises one, two, or all three of the VH CDRs above.

In some embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof, which specifically binds to human FAM19A5, comprises:

(a) a VL CDR1 comprising the amino acid sequence of SEQ ID NO: 32; and/or (b) a VL CDR2 comprising the amino acid sequence of SEQ ID NO: 33; and/or (c) a VL CDR3 comprising the amino acid sequence of SEQ ID NO: 34.

In specific embodiments, the antibody or antigen-binding portion thereof comprises one, two, or all three of the VL CDRs above.

In some embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof, which specifically binds to human FAM19A5, comprise:

(a) a VH CDR1 comprising the amino acid sequence of SEQ ID NO: 20; (b) a VH CDR2 comprising the amino acid sequence of SEQ ID NO: 21; (c) a VH CDR3 comprising the amino acid sequence of SEQ ID NO: 22; (d) a VL CDR1 comprising the amino acid sequence of SEQ ID NO: 32; (e) a VL CDR2 comprising the amino acid sequence of SEQ ID NO: 33; and/or (f) a VL CDR3 comprising the amino acid sequence of SEQ ID NO: 34.

In specific embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof comprises one, two, three, four, five, or six of the CDRs above.

A VH domain, or one or more CDRs thereof, described herein can be linked to a constant domain for forming a heavy chain, e.g., a full length heavy chain. Similarly, a VL domain, or one or more CDRs thereof, described herein can be linked to a constant domain for forming a light chain, e.g., a full length light chain. A full length heavy chain and full length light chain combine to form a full length antibody.

Accordingly, in specific embodiments, provided herein is an antibody comprising an antibody light chain and heavy chain, e.g., a separate light chain and heavy chain. With respect to the light chain, in a specific embodiment, the light chain of an antibody described herein is a kappa light chain. In another specific embodiment, the light chain of an antibody described herein is a lambda light chain. In yet another specific embodiment, the light chain of an antibody described herein is a human kappa light chain or a human lambda light chain. In a particular embodiment, an antibody described herein, which specifically binds to an FAM19A5 polypeptide (e.g., human FAM19A5) comprises a light chain which comprises any VL or VL CDR amino acid sequences described herein, and wherein the constant region of the light chain comprises the amino acid sequence of a human kappa light chain constant region. In a particular embodiment, an antibody described herein, which specifically binds to an FAM19A5 polypeptide (e.g., human FAM19A5) comprises a light chain which comprises a VL or VL CDR amino acid sequences described herein, and wherein the constant region of the light chain comprises the amino acid sequence of a human lambda light chain constant region. Non-limiting examples of human constant region sequences have been described in the art, e.g., see U.S. Pat. No. 5,693,780 and Kabat E A et al, (1991) supra.

With respect to the heavy chain, in some embodiments, the heavy chain of an antibody described herein can be an alpha (α), delta (δ), epsilon (ε), gamma (γ) or mu (μ) heavy chain. In another specific embodiment, the heavy chain of an antibody described can comprise a human alpha (α), delta (δ), epsilon (ε), gamma (γ) or mu (μ) heavy chain. In one embodiment, an antibody described herein, which specifically binds to FAM19A5 (e.g., human FAM19A5), comprises a heavy chain which comprises a VH or VH CDR amino acid sequence described herein, and wherein the constant region of the heavy chain comprises the amino acid sequence of a human gamma (γ) heavy chain constant region. In another embodiment, an antibody described herein, which specifically binds to FAM19A5 (e.g., human FAM19A5), comprises a heavy chain which comprises a VH or VH CDR amino acid sequence disclosed herein, and wherein the constant region of the heavy chain comprises the amino acid of a human heavy chain described herein or known in the art. Non-limiting examples of human constant region sequences have been described in the art, e.g., see U.S. Pat. No. 5,693,780 and Kabat E A et al., (1991) supra.

In some embodiments, an antibody described herein, which specifically binds to FAM19A5 (e.g., human FAM19A5) comprises a VL domain and a VH domain comprising the VH or VH CDRs and VL and VL CDRs described herein, and wherein the constant regions comprise the amino acid sequences of the constant regions of an IgG, IgE, IgM, IgD, IgA or IgY immunoglobulin molecule, or a human IgG, IgE, IgM, IgD, IgA or IgY immunoglobulin molecule. In another specific embodiment, an antibody described herein, which specifically binds to FAM19A5 (e.g., human FAM19A5) comprises a VL domain and a VH domain comprising any amino acid sequences described herein, and wherein the constant regions comprise the amino acid sequences of the constant regions of an IgG, IgE, IgM, IgD, IgA or IgY immunoglobulin molecule, any subclass (e.g., IgG1, IgG2, IgG3, IgG4, IgA1 and IgA2) of immunoglobulin molecule. In some embodiments, the constant regions comprise the amino acid sequences of the constant regions of a human IgG, which are naturally-occurring, including subclasses (e.g., IgG1, IgG2, IgG3 or IgG4), and allotypes (e.g., G1m, G2m, G3m, and nG4m) and variants thereof. See, e.g., Vidarsson G. et al. Front Immunol. 5:520 (published online Oct. 20, 2014) and Jefferis R. and Lefranc M P, mAbs 1:4, 1-7(2009). In some embodiments, the constant regions comprise the amino acid sequences of the constant regions of a human IgG1, IgG2, IgG3, or IgG4, or variants thereof.

In certain embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof disclosed herein does not have Fc effector functions, e.g., complement-dependent cytotoxicity (CDC) and/or antibody-dependent cellular phagocytosis (ADCP). Effector functions are mediated by the Fc region and the residues most proximal to the hinge region in the CH2 domain of the Fc region are responsible for effector functions of antibodies as it contains a largely overlapping binding site for C1q (complement) and IgG-Fc receptors (FcγR) on effector cells of the innate immune system. Also, IgG2 and IgG4 antibodies have lower levels of Fc effector functions than IgG1 and IgG3 antibodies. Effector functions of an antibody can be reduced or avoided by different approaches known in the art, including (1) using antibody fragments lacking the Fc region (e.g., such as a Fab, F(ab′)₂, single chain Fv (scFv), or a sdAb consisting of a monomeric VH or VL domain); (2) generating aglycosylated antibodies, which can be generated by, for example, deleting or altering the residue the sugar is attached to, removing the sugars enzymatically, producing the antibody in cells cultured in the presence of a glycosylation inhibitor, or by expressing the antibody in cells unable to glycosylate proteins (e.g., bacterial host cells, see, e.g., U.S. Pub. No. 20120100140); (3) employing Fc regions from an IgG subclass that have reduced effector function (e.g., an Fc region from IgG2 or IgG4 antibodies or a chimeric Fc region comprising a CH2 domain from IgG2 or IgG4 antibodies, see, e.g., U.S. Pub. No. 20120100140 and Lau C. et al. J. Immunol. 191:4769-4777 (2013)); and (4) generating an Fc region with mutations that result in reduced or no Fc functions. See, e.g., U.S. Pub. No. 20120100140 and U.S. and PCT applications cited therein and An et al. mAbs 1:6, 572-579 (2009).

Thus, in some embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof disclosed herein is an Fab, an Fab′, an F(ab′)2, an Fv, a single chain Fv (scFv), or a sdAb consisting of a monomeric VH or VL domain. Such antibody fragments are well known in the art and are described supra.

In some embodiments, the anti-FAM19A5 antibody or antigen-binding portion thereof disclosed herein comprises an Fc region with reduced or no Fc effector function. In some embodiments, the constant regions comprise the amino acid sequences of the Fc region of a human IgG2 or IgG4, in some embodiments, the anti-FAM19A5 antibody is of an IgG2/IgG4 isotype. In some embodiments, the anti-FAM19A5 antibody comprises a chimeric Fc region which comprises a CH2 domain from an IgG antibody of the IgG4 isotype and a CH3 domain from an IgG antibody of the IgG1 isotype, or a chimeric Fc region which comprises a hinge region from IgG2 and a CH2 region from IgG4, or an Fc region with mutations that result in reduced or no Fc functions. Fc regions with reduced or no Fc effector function include those known in the art. See e.g., Lau C. et al. J. Immunol. 191:4769-4777 (2013); An et al., mAbs 1:6, 572-579 (2009); and U.S. Pub. No. 20120100140 and the U.S. patents and publications and PCT publications cited therein. Also Fc regions with reduced or no Fc effector function can be readily made by a person of ordinary skill in the art.

VI. Nucleic Acid Molecules

Another aspect described herein pertains to one or more nucleic acid molecules that encode any one of the antibodies or antigen-binding portions thereof described herein. The nucleic acids can be present in whole cells, in a cell lysate, or in a partially purified or substantially pure form. A nucleic acid is “isolated” or “rendered substantially pure” when purified away from other cellular components or other contaminants, e.g., other cellular nucleic acids (e.g., other chromosomal DNA, e.g., the chromosomal DNA that is linked to the isolated DNA in nature) or proteins, by standard techniques, including alkaline/SDS treatment, CsCl banding, column chromatography, restriction enzymes, agarose gel electrophoresis and others well known in the art. See, F. Ausubel, et al., ed. (1987) Current Protocols in Molecular Biology, Greene Publishing and Wiley Interscience, New York. A nucleic acid described herein can be, for example, DNA or RNA and can or cannot contain intronic sequences. In a certain embodiments, the nucleic acid is a cDNA molecule.

Nucleic acids described herein can be obtained using standard molecular biology techniques. For antibodies expressed by hybridomas (e.g., hybridomas prepared from transgenic mice carrying human immunoglobulin genes as described further below), cDNAs encoding the light and heavy chains of the antibody made by the hybridoma can be obtained by standard PCR amplification or cDNA cloning techniques. For antibodies obtained from an immunoglobulin gene library (e.g., using phage display techniques), nucleic acid encoding the antibody can be recovered from the library.

Certain nucleic acids molecules described herein are those encoding the VH and VL sequences of the various anti-FAM19A5 antibodies of the present disclosure. Exemplary DNA sequences encoding the VH sequence of such antibodies are set forth in SEQ ID NOs: 43-46 and 177. Exemplary DNA sequences encoding the VL sequences of such antibodies are set forth in SEQ ID NOs: 47-50 and 178.

TABLE 6 Variable heavy chain polynucleotide sequence Antibody Variable Heavy Chain Polynucleotide Sequence (SEQ ID NO) Anti-FAM19A5 GCCGTGACGTTGGACGAGTCCGGGGGCGGCCTCCAGACGCCCGGAGGAGCGCTCAGCCTC (2-13) GTCTGCAAGGCCTCCGGGTTCACCTTCAGCAGCCATGGCATGTTCTGGGTGCGACAGACG CCCGGCAAGGGGTTGGAATATGTCGCTGAAATTACCAATGATGGTAGTGGCACAAACTAC GGGTCGGCGGTGAAGGGCCGTGCCACCATCTCGAGGGACAACGGGCAGAGCACAGTGAGG CTGCAGCTGAACAACCTCAGGGCTGAGGACACCGGCACCTACTTCTGCGCCAGATCTACT TATGAATGTCCTGGTGGTTTTAGTTGTTGGGGTGATACTGGTCAAATAGACGCATGGGGC CACGGGACCGAAGTCATCGTCTCCTCCA (SEQ ID NO: 43) Anti-FAM19A5 GCCGTGACGTTGGACGAGTCCGGGGGCGGCCTCCAGACGCCCGGAGGAGCGCTCAGCCTC (3-2) GTCTGCAAGGCCTCCGGGTTCACCTTCAGCAGCTTCAACATGTTCTGGGTGCGACAGGCG CCCGGCAAGGGGCTGGAATACGTCGCTCAAATTAGCAGCAGTGGTAGTAGCACAAACTAC GCACCCGCGGTGAGGGGCCGTGCCACCATCTCGAGGGACAACGGGCAGAGCACAGTGAGG CTGCAGCTGAACAACCCCGGGGCTGAAGACACCGGCACCTACTACTGCGCCAAAAGTAGT TATGACTGTCCTTACGGTCATTGTAGTAGTGGTGTTGATAGTGCTGGTGAGATCGACGCA TGGGGCCACGGGACCGAAGTCATCGTCTCCTCCA (SEQ ID NO: 44) Anti-FAM19A5 GCCGTGACACTGGACGAATCTGGGGGAGGGCTGCAGACTCCAGGCGGAGCTCTGAGCCTG (1-65) GTGTGCAAGGCATCCGGGTTCACCTTTAGCTCCTACCAGATGGGATGGGTGCGGCAGGCA CCAGGGAAGGGCCTGGAGTGGGTCGGAGTGATCAACAAATCTGGGAGTGACACAAGCTAC GGCAGCGCCGTGAAGGGAAGGGCCACCATCAGCAGGGACAATGGCCAGAGTACCGTGCGG CTGCAGCTGAACAATCTGCGCGCTGAGGACACTGGCACCTACTTCTGTGCTAAGGGATCA GCAAGCTATATCACAGCCGCTACTATTGATGCATGGGGACACGGGACAGAAGTCATCGTG TCTAGT (SEQ ID NO: 45) Anti-FAM19A5 GCCGTGACGTTGGACGAGTCCGGGGGCGGCCTCCAGACGCCCGGAGGAGCGCTCAGCCTC (1-28) GTCTGCAAGGCCTCCGGGTTCGACTTCAGCGATTATGGCATGGGTTGGGTGCGACAGGCT CCAGGCAAGGGGCTGGAGTGGGTTGCTGCTATTAGAAGTGATGGTAGTAACCCATCATAC GGGTCGGCGGTGAAGGGCCGTGCCACCATCTCGAAGGACAACGGGCGAAGCACAGTGAGG CTGCAGCTGAACAACCTCAGGGCTGAGGACACCGCCACCTACTACTGCGCCAAGGATGGT AATGGTTACTGTGCTCTCGATGCTTATCGTAGTGGTGGTTATAGTTGTGGTGTTTATCCT GGTAGCATCGACGCATGGGGCCACGGGACCGAAGTCATCGTCTCCTCC (SEQ ID NO: 46) Anti-FAM19A5 CAGTCGCTGGAGGAGTCCGGGGGTCGCCTGGTCACGCCTGGGACACCCCTGACACTCACC (P2-C12) TGCACCGTCTCTGGATTCTCCCTCAGTACCTATGCAGTGACCTGGGTCCGCCAGGCTCCA GGGAAGGGGCTGGAATGGATCGGATACATTAATTGGCGTGGTGGGACATCCTACGCGAAC TGGGCGAAAGGCCGATTCACCATCTCCAAAACCTCGTCGACCACGGTGGATCTGAAAATG ACCAGTCCGACAACCGAGGACACGGCCACCTATTTCTGTGCCAGAGATGCTAGTAGTGGT GCTGCTTTTGGGTCTTACGGCATGGACCCCTGGGGCCCAGGGACCCTCGTCACCGTCTCT TCA (SEQ ID NO: 177)

TABLE 7 Variable light chain polynucleotide sequence Antibody Variable Light Chain Polynucleotide Sequence (SEQ ID NO) Anti-FAM19A5 GGCCCTGACTCAGCCGTCCTCGGTGTCAGCAAACCCAGGAGAAACCGTCAAGATAACCTG (2-13) CTCCGGGGGTAGCTATAGCTATGGCTGGTTCCAGCAGAAGTCTCCTGGCAGTGCCCTTGT CACTGTGATCTACTGGGATGATGAGAGACCCTCGGACATCCCTTCACGATTCTCCGGTGC CCTATCCGGCTCCACAAACACATTAACCATCACTGGGGTCCAAGCCGACGACGAGGCTGT CTATTTCTGTGGGACTGAAGACATCAGCGGCACTGCTGGTGTATTTGGGGCCGGGACAAC CCTGACCGTCCTGGG (SEQ ID NO: 47) Anti-FAM19A5 GGCCCTGACTCAGCCGTCCTCGGTGTCAGCAAACCCAGGAGAAACCGTCAAGATCACCTG (3-2) CTCCGGGGGTGGCAGCTATGCTGGAAGTTACTATTATGGCTGGTACCAGCAGAAGGCACC TGGCAGTGCCCCTGTCACTCTGATCTATGAAAGCAACAAGAGACCCTCGGACATCCCTTC ACGATTCTCCGGTTCCACATCTGGCTCCACAGCCACACTAACCATCACTGGGGTCCAAGC CGATGACGAGGCTATCTATTACTGTGGGAGCTGGGACAGTAGCAATGGTGGTATATTTGG GGCCGGGACAACCCTGACCGTCCTAGG (SEQ ID NO: 48) Anti-FAM19A5 GCCCTGACTCAGCCCTCTTCCGTGTCAGCCAACCCTGGAGAAACTGTGAAGATCACCTGC (1-65) AGCGGAGGAGGGAGCTCCGGATACGGATATGGGTGGTATCAGCAGAAATCCCCATCTAGT GCCCCCCTGACTGTGATCTATTGGAACGACAAGAGGCCTAGTGATATTCCATCAAGATTC AGTGGATCAAAAAGCGGGTCCACTCACACCCTGACAATCACTGGCGTGCAGGCAGAGGAC GAAGCCGTCTACTTCTGCGGAAATGACGATTACTCAAGCGATTCTGGCTATGTGGGCGTC TTTGGCGCAGGAACCACACTGACAGTGCTG (SEQ ID NO: 49) Anti-FAM19A5 GCCCTGACTCAGCCGTCCTCGGTGTCAGCAAACCTGGAAGGAACCGTCGAGATCACCTGC (1-28) TCCGGGAGTGGCTATGGTTATGGCTGGTATCAGCAGAAGTCTCCTGGCAGTGCCCCTGTC ACTGTGATCTATCAGAACGACAAGAGACCCTCGGACATCCCTTCACGATTCTCCGGTTCC AAATCCGGCTCCACGGGCACATTAACCATCACTGGGGTCCAAGTCGAGGACGAGGCTGTC TATTACTGTGGGAGTGAAGACAGCAGCACTCTTGCTGGTATATTTGGGGCCGGGACAACC CTGACCGTCCTA (SEQ ID NO: 50) Anti-FAM19A5 GAGCTCGATATGACCCAGACTCCATCCTCCGTGTCTGCAGCTGTGGGAGGCACAGTCACC (P2-C12) ATCAAGTGCCAGGCCAGTCAGAGCATTAGTAGCTACTTATCCTGGTATCAGCAGAAACCA GGGCAGCCTCCCAAGCTCCTGATCTATGAAGCATCCAAACTGGCCTCTGGGGTCCCATCG CGGTTCAGCGGCAGTGGATATGGGACAGAGTTCACTCTCACCATCAGCGACCTGGAGTGT GCCGATGCTGCCACTTACTACTGTCAACAGGGTTATAGTAGTACTAATGTTTGGAATGCT TTCGGCGGAGGCACCAATGTGGAAATCAAA (SEQ ID NO: 178)

A method for making an anti-FAM19A5 antibody as disclosed herewith can comprise expressing the relevant heavy chain and light chain of the antibody in a cell line comprising the nucleotide sequences encoding the heavy and light chains with a signal peptide, e.g., SEQ ID NOs: 43 and 47, SEQ ID NOs: 44 and 48, SEQ ID NOs: 45 and 49, SEQ ID NOs: 46 and 50, SEQ ID NOs: 177 and 178, respectively. Host cells comprising these nucleotide sequences are encompassed herein.

Once DNA fragments encoding VH and VL segments are obtained, these DNA fragments can be further manipulated by standard recombinant DNA techniques, for example to convert the variable region genes to full-length antibody chain genes, to Fab fragment genes or to a scFv gene. In these manipulations, a VL- or VH-encoding DNA fragment is operatively linked to another DNA fragment encoding another protein, such as an antibody constant region or a flexible linker. The term “operatively linked”, as used in this context, is intended to mean that the two DNA fragments are joined such that the amino acid sequences encoded by the two DNA fragments remain in-frame.

The isolated DNA encoding the VH region can be converted to a full-length heavy chain gene by operatively linking the VH-encoding DNA to another DNA molecule encoding heavy chain constant regions (hinge, CH1, CH2 and/or CH3). The sequences of human heavy chain constant region genes are known in the art (see, e.g., Kabat, E. A., et al., (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242) and DNA fragments encompassing these regions can be obtained by standard PCR amplification. The heavy chain constant region can be an IgG1, IgG2, IgG3, IgG4, IgA, IgE, IgM or IgD constant region, for example, an IgG2 and/or IgG 4 constant region. For a Fab fragment heavy chain gene, the VH-encoding DNA can be operatively linked to another DNA molecule encoding only the heavy chain CH1 constant region.

The isolated DNA encoding the VL region can be converted to a full-length light chain gene (as well as a Fab light chain gene) by operatively linking the VL-encoding DNA to another DNA molecule encoding the light chain constant region, CL. The sequences of human light chain constant region genes are known in the art (see, e.g., Kabat, E. A., et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242) and DNA fragments encompassing these regions can be obtained by standard PCR amplification. The light chain constant region can be a kappa or lambda constant region.

To create a scFv gene, the VH- and VL-encoding DNA fragments are operatively linked to another fragment encoding a flexible linker, e.g., encoding the amino acid sequence (Gly4-Ser)3, such that the VH and VL sequences can be expressed as a contiguous single-chain protein, with the VL and VH regions joined by the flexible linker (see, e.g., Bird et al. (1988) Science 242:423-426; Huston et al. (1988) Proc. Natl. Acad. Sci. USA 85:5879-5883; McCafferty et al., (1990) Nature 348:552-554).

In some embodiments, the present disclosure provides a vector comprising an isolated nucleic acid molecule comprising a nucleotide sequence encoding an antibody or antigen-binding portion thereof. In other embodiments, the vectors can be used for gene therapy.

Suitable vectors for the disclosure include expression vectors, viral vectors, and plasmid vectors. In one embodiment, the vector is a viral vector.

As used herein, an expression vector refers to any nucleic acid construct which contains the necessary elements for the transcription and translation of an inserted coding sequence, or in the case of an RNA viral vector, the necessary elements for replication and translation, when introduced into an appropriate host cell. Expression vectors can include plasmids, phagemids, viruses, and derivatives thereof.

Expression vectors of the disclosure can include polynucleotides encoding the antibody or antigen-binding portion thereof described herein. In one embodiment, the coding sequences for the antibody or antigen-binding portion thereof is operably linked to an expression control sequence. As used herein, two nucleic acid sequences are operably linked when they are covalently linked in such a way as to permit each component nucleic acid sequence to retain its functionality. A coding sequence and a gene expression control sequence are said to be operably linked when they are covalently linked in such a way as to place the expression or transcription and/or translation of the coding sequence under the influence or control of the gene expression control sequence. Two DNA sequences are said to be operably linked if induction of a promoter in the 5′ gene expression sequence results in the transcription of the coding sequence and if the nature of the linkage between the two DNA sequences does not (1) result in the introduction of a frame-shift mutation, (2) interfere with the ability of the promoter region to direct the transcription of the coding sequence, or (3) interfere with the ability of the corresponding RNA transcript to be translated into a protein. Thus, a gene expression sequence would be operably linked to a coding nucleic acid sequence if the gene expression sequence were capable of effecting transcription of that coding nucleic acid sequence such that the resulting transcript is translated into the desired antibody or antigen-binding portion thereof.

Viral vectors include, but are not limited to, nucleic acid sequences from the following viruses: retrovirus, such as Moloney murine leukemia virus, Harvey murine sarcoma virus, murine mammary tumor virus, and Rous sarcoma virus; lentivirus; adenovirus; adeno-associated virus; SV40-type viruses; polyomaviruses; Epstein-Barr viruses; papilloma viruses; herpes virus; vaccinia virus; polio virus; and RNA virus such as a retrovirus. One can readily employ other vectors well-known in the art. Certain viral vectors are based on non-cytopathic eukaryotic viruses in which non-essential genes have been replaced with the gene of interest. Non-cytopathic viruses include retroviruses, the life cycle of which involves reverse transcription of genomic viral RNA into DNA with subsequent proviral integration into host cellular DNA. Retroviruses have been approved for human gene therapy trials. Most useful are those retroviruses that are replication-deficient (i.e., capable of directing synthesis of the desired proteins, but incapable of manufacturing an infectious particle). Such genetically altered retroviral expression vectors have general utility for the high efficiency transduction of genes in vivo. Standard protocols for producing replication-deficient retroviruses (including the steps of incorporation of exogenous genetic material into a plasmid, transfection of a packaging cell line with plasmid, production of recombinant retroviruses by the packaging cell line, collection of viral particles from tissue culture media, and infection of the target cells with viral particles) are provided in Kriegler, M., Gene Transfer and Expression, A Laboratory Manual, W.H. Freeman Co., New York (1990) and Murry, E. J., Methods in Molecular Biology, Vol. 7, Humana Press, Inc., Cliffton, N.J. (1991).

In one embodiment, the virus is an adeno-associated virus, a double-stranded DNA virus. The adeno-associated virus can be engineered to be replication-deficient and is capable of infecting a wide range of cell types and species. It further has advantages such as heat and lipid solvent stability; high transduction frequencies in cells of diverse lineages, including hematopoietic cells; and lack of superinfection inhibition thus allowing multiple series of transductions. Reportedly, the adeno-associated virus can integrate into human cellular DNA in a site-specific manner, thereby minimizing the possibility of insertional mutagenesis and variability of inserted gene expression characteristic of retroviral infection. In addition, wild-type adeno-associated virus infections have been followed in tissue culture for greater than 100 passages in the absence of selective pressure, implying that the adeno-associated virus genomic integration is a relatively stable event. The adeno-associated virus can also function in an extrachromosomal fashion.

In other embodiments, the vector is derived from lentivirus. In certain embodiments, the vector is a vector of a recombinant lentivirus capable of infecting non-dividing cells.

The lentiviral genome and the proviral DNA typically have the three genes found in retroviruses: gag, pol and env, which are flanked by two long terminal repeat (LTR) sequences. The gag gene encodes the internal structural (matrix, capsid and nucleocapsid) proteins; the pol gene encodes the RNA-directed DNA polymerase (reverse transcriptase), a protease and an integrase; and the env gene encodes viral envelope glycoproteins. The 5′ and 3′ LTR's serve to promote transcription and polyadenylation of the virion RNA's. The LTR contains all other cis-acting sequences necessary for viral replication. Lentiviruses have additional genes including vif, vpr, tat, rev, vpu, nef and vpx (in HIV-1, HIV-2 and/or SIV).

Adjacent to the 5′ LTR are sequences necessary for reverse transcription of the genome (the tRNA primer binding site) and for efficient encapsidation of viral RNA into particles (the Psi site). If the sequences necessary for encapsidation (or packaging of retroviral RNA into infectious virions) are missing from the viral genome, the cis defect prevents encapsidation of genomic RNA.

However, the resulting mutant remains capable of directing the synthesis of all virion proteins. The disclosure provides a method of producing a recombinant lentivirus capable of infecting a non-dividing cell comprising transfecting a suitable host cell with two or more vectors carrying the packaging functions, namely gag, pol and env, as well as rev and tat. As will be disclosed herein below, vectors lacking a functional tat gene are desirable for certain applications. Thus, for example, a first vector can provide a nucleic acid encoding a viral gag and a viral pol and another vector can provide a nucleic acid encoding a viral env to produce a packaging cell. Introducing a vector providing a heterologous gene, herein identified as a transfer vector, into that packaging cell yields a producer cell which releases infectious viral particles carrying the foreign gene of interest.

According to the above-indicated configuration of vectors and foreign genes, the second vector can provide a nucleic acid encoding a viral envelope (env) gene. The env gene can be derived from nearly any suitable virus, including retroviruses. In some embodiments, the env protein is an amphotropic envelope protein which allows transduction of cells of human and other species.

Examples of retroviral-derived env genes include, but are not limited to: Moloney murine leukemia virus (MoMuLV or MMLV), Harvey murine sarcoma virus (HaMuSV or HSV), murine mammary tumor virus (MuMTV or MMTV), gibbon ape leukemia virus (GaLV or GALV), human immunodeficiency virus (HIV) and Rous sarcoma virus (RSV). Other env genes such as Vesicular stomatitis virus (VSV) protein G (VSV G), that of hepatitis viruses and of influenza also can be used.

The vector providing the viral env nucleic acid sequence is associated operably with regulatory sequences described elsewhere herein.

In certain embodiments, the vector includes a lentiviral vector in which the HIV virulence genes env, vif, vpr, vpu and nef were deleted without compromising the ability of the vector to transduce non-dividing cells.

In some embodiments, the vector includes a lentiviral vector which comprises a deletion of the U3 region of the 3′ LTR. The deletion of the U3 region can be the complete deletion or a partial deletion.

In some embodiments, the lentiviral vector of the disclosure comprising the FVIII nucleotide sequence described herein can be transfected in a cell with (a) a first nucleotide sequence comprising a gag, a pol, or gag and pol genes and (b) a second nucleotide sequence comprising a heterologous env gene; wherein the lentiviral vector lacks a functional tat gene. In other embodiments, the cell is further transfected with a fourth nucleotide sequence comprising a rev gene. In certain embodiments, the lentiviral vector lacks functional genes selected from vif, vpr, vpu, vpx and nef, or a combination thereof.

In certain embodiments, a lentiviral vector comprises one or more nucleotide sequences encoding a gag protein, a Rev-response element, a central polypurine track (cPPT), or any combination thereof.

Examples of the lentiviral vectors are disclosed in WO9931251, WO9712622,

WO9817815, WO9817816, and WO9818934, which are incorporated herein by reference in their entireties.

Other vectors include plasmid vectors. Plasmid vectors have been extensively described in the art and are well-known to those of skill in the art. See, e.g., Sambrook et al., Molecular Cloning: A Laboratory Manual, Second Edition, Cold Spring Harbor Laboratory Press, 1989. In the last few years, plasmid vectors have been found to be particularly advantageous for delivering genes to cells in vivo because of their inability to replicate within and integrate into a host genome. These plasmids, however, having a promoter compatible with the host cell, can express a peptide from a gene operably encoded within the plasmid. Some commonly used plasmids available from commercial suppliers include pBR322, pUC18, pUC19, various pcDNA plasmids, pRC/CMV, various pCMV plasmids, pSV40, and pBlueScript. Additional examples of specific plasmids include pcDNA3.1, catalog number V79020; pcDNA3.1/hygro, catalog number V87020; pcDNA4/myc-His, catalog number V86320; and pBudCE4.1, catalog number V53220, all from Invitrogen (Carlsbad, Calif.). Other plasmids are well-known to those of ordinary skill in the art. Additionally, plasmids can be custom designed using standard molecular biology techniques to remove and/or add specific fragments of DNA.

VII. Antibody Production

Antibodies or fragments thereof that immunospecifically bind to FAM19A5 (e.g., human FAM19A5) can be produced by any method known in the art for the synthesis of antibodies, for example, by chemical synthesis or by recombinant expression techniques. The methods described herein employs, unless otherwise indicated, conventional techniques in molecular biology, microbiology, genetic analysis, recombinant DNA, organic chemistry, biochemistry, PCR, oligonucleotide synthesis and modification, nucleic acid hybridization, and related fields within the skill of the art. These techniques are described, for example, in the references cited herein and are fully explained in the literature. See, e.g., Maniatis T et al., (1982) Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press; Sambrook J et al., (1989), Molecular Cloning: A Laboratory Manual, Second Edition, Cold Spring Harbor Laboratory Press; Sambrook J et al., (2001) Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.; Ausubel F M et al., Current Protocols in Molecular Biology, John Wiley & Sons (1987 and annual updates); Current Protocols in Immunology, John Wiley & Sons (1987 and annual updates) Gait (ed.) (1984) Oligonucleotide Synthesis: A Practical Approach, IRL Press; Eckstein (ed.) (1991) Oligonucleotides and Analogues: A Practical Approach, IRL Press; Birren B et al., (eds.) (1999) Genome Analysis: A Laboratory Manual, Cold Spring Harbor Laboratory Press.

In a specific embodiment, an antibody described herein is an antibody (e.g., recombinant antibody) prepared, expressed, created or isolated by any means that involves creation, e.g., via synthesis, genetic engineering of DNA sequences. In certain embodiments, such antibody comprises sequences (e.g., DNA sequences or amino acid sequences) that do not naturally exist within the antibody germline repertoire of an animal or mammal (e.g., human) in vivo.

VIII. Pharmaceutical Compositions

Further provided herein are compositions comprising an antibody or antigen-binding portion thereof described herein (e.g., anti-FAM19A5 antibody) having the desired degree of purity in a physiologically acceptable carrier, excipient or stabilizer (Remington's Pharmaceutical Sciences (1990) Mack Publishing Co., Easton, Pa.). Acceptable carriers, excipients, or stabilizers are nontoxic to recipients at the dosages and concentrations employed, and include buffers such as phosphate, citrate, and other organic acids; antioxidants including ascorbic acid and methionine; preservatives (such as octadecyldimethylbenzyl ammonium chloride; hexamethonium chloride; benzalkonium chloride, benzethonium chloride; phenol, butyl or benzyl alcohol; alkyl parabens such as methyl or propyl paraben; catechol; resorcinol; cyclohexanol; 3-pentanol; and m-cresol); low molecular weight (less than about 10 residues) polypeptides; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, histidine, arginine, or lysine; monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugars such as sucrose, mannitol, trehalose or sorbitol; salt-forming counter-ions such as sodium; metal complexes (e.g., Zn-protein complexes); and/or non-ionic surfactants such as TWEEN®, PLURONICS® or polyethylene glycol (PEG).

In some embodiments, pharmaceutical compositions comprise an antibody or antigen-binding portion thereof, a bispecific molecule, or a immunoconjugate described herein, and optionally one or more additional prophylactic or therapeutic agents, in a pharmaceutically acceptable carrier. In certain embodiments, pharmaceutical compositions comprise an effective amount of an antibody or antigen-binding portion thereof described herein, and optionally one or more additional prophylactic of therapeutic agents, in a pharmaceutically acceptable carrier. In some embodiments, the antibody is the only active ingredient included in the pharmaceutical composition. Pharmaceutical compositions described herein can be useful in reducing a FAM19A5 activity, and thereby treat a fibrotic disease or condition, such as liver fibrosis and/or pulmonary fibrosis.

Pharmaceutically acceptable carriers used in parenteral preparations include aqueous vehicles, nonaqueous vehicles, antimicrobial agents, isotonic agents, buffers, antioxidants, local anesthetics, suspending and dispersing agents, emulsifying agents, sequestering or chelating agents and other pharmaceutically acceptable substances. Examples of aqueous vehicles include Sodium Chloride Injection, Ringers Injection, Isotonic Dextrose Injection, Sterile Water Injection, Dextrose and Lactated Ringers Injection. Nonaqueous parenteral vehicles include fixed oils of vegetable origin, cottonseed oil, corn oil, sesame oil and peanut oil. Antimicrobial agents in bacteriostatic or fungistatic concentrations can be added to parenteral preparations packaged in multiple-dose containers which include phenols or cresols, mercurials, benzyl alcohol, chlorobutanol, methyl and propyl p-hydroxybenzoic acid esters, thimerosal, benzalkonium chloride and benzethonium chloride. Isotonic agents include sodium chloride and dextrose. Buffers include phosphate and citrate. Antioxidants include sodium bisulfate. Local anesthetics include procaine hydrochloride. Suspending and dispersing agents include sodium carboxymethylcelluose, hydroxypropyl methylcellulose and polyvinylpyrrolidone. Emulsifying agents include Polysorbate 80 (TWEEN® 80). A sequestering or chelating agent of metal ions includes EDTA. Pharmaceutical carriers also include ethyl alcohol, polyethylene glycol and propylene glycol for water miscible vehicles; and sodium hydroxide, hydrochloric acid, citric acid or lactic acid for pH adjustment.

A pharmaceutical composition can be formulated for any route of administration to a subject. Specific examples of routes of administration include intranasal, oral, parenterally, intrathecally, intra-cerebroventricularly, pulmonarily, subcutaneously, or intraventricularly. Parenteral administration, characterized by either subcutaneous, intramuscular or intravenous injection, is also contemplated herein. Injectables can be prepared in conventional forms, either as liquid solutions or suspensions, solid forms suitable for solution or suspension in liquid prior to injection, or as emulsions. The injectables, solutions and emulsions also contain one or more excipients. Suitable excipients are, for example, water, saline, dextrose, glycerol or ethanol. In addition, if desired, the pharmaceutical compositions to be administered can also contain minor amounts of non-toxic auxiliary substances such as wetting or emulsifying agents, pH buffering agents, stabilizers, solubility enhancers, and other such agents, such as for example, sodium acetate, sorbitan monolaurate, triethanolamine oleate and cyclodextrins.

Preparations for parenteral administration of an antibody include sterile solutions ready for injection, sterile dry soluble products, such as lyophilized powders, ready to be combined with a solvent just prior to use, including hypodermic tablets, sterile suspensions ready for injection, sterile dry insoluble products ready to be combined with a vehicle just prior to use and sterile emulsions. The solutions can be either aqueous or nonaqueous.

If administered intravenously, suitable carriers include physiological saline or phosphate buffered saline (PBS), and solutions containing thickening and solubilizing agents, such as glucose, polyethylene glycol, and polypropylene glycol and mixtures thereof.

Topical mixtures comprising an antibody are prepared as described for the local and systemic administration. The resulting mixture can be a solution, suspension, emulsions or the like and can be formulated as creams, gels, ointments, emulsions, solutions, elixirs, lotions, suspensions, tinctures, pastes, foams, aerosols, irrigations, sprays, suppositories, bandages, dermal patches or any other formulations suitable for topical administration.

An antibody or antigen-binding portion thereof described herein can be formulated as an aerosol for topical application, such as by inhalation (see, e.g., U.S. Pat. Nos. 4,044,126, 4,414,209 and 4,364,923, which describe aerosols for delivery of a steroid useful for treatment of inflammatory diseases, particularly asthma). These formulations for administration to the respiratory tract can be in the form of an aerosol or solution for a nebulizer, or as a microtine powder for insufflations, alone or in combination with an inert carrier such as lactose. In such a case, the particles of the formulation will, in one embodiment, have diameters of less than 50 microns, in one embodiment less than 10 microns.

An antibody or antigen-binding portion thereof described herein can be formulated for local or topical application, such as for topical application to the skin and mucous membranes, such as in the eye, in the form of gels, creams, and lotions and for application to the eye or for intracisternal or intraspinal application. Topical administration is contemplated for transdermal delivery and also for administration to the eyes or mucosa, or for inhalation therapies. Nasal solutions of the antibody alone or in combination with other pharmaceutically acceptable excipients can also be administered.

Transdermal patches, including iontophoretic and electrophoretic devices, are well known to those of skill in the art, and can be used to administer an antibody. For example, such patches are disclosed in U.S. Pat. Nos. 6,267,983, 6,261,595, 6,256,533, 6,167,301, 6,024,975, 6,010715, 5,985,317, 5,983,134, 5,948,433, and 5,860,957.

In certain embodiments, a pharmaceutical composition comprising an antibody or antigen-binding portion thereof described herein is a lyophilized powder, which can be reconstituted for administration as solutions, emulsions and other mixtures. It can also be reconstituted and formulated as solids or gels. The lyophilized powder is prepared by dissolving an antibody or antigen-binding portion thereof described herein, or a pharmaceutically acceptable derivative thereof, in a suitable solvent. In some embodiments, the lyophilized powder is sterile. The solvent can contain an excipient which improves the stability or other pharmacological component of the powder or reconstituted solution, prepared from the powder. Excipients that can be used include, but are not limited to, dextrose, sorbitol, fructose, corn syrup, xylitol, glycerin, glucose, sucrose or other suitable agent. The solvent can also contain a buffer, such as citrate, sodium or potassium phosphate or other such buffer known to those of skill in the art at, in one embodiment, about neutral pH. Subsequent sterile filtration of the solution followed by lyophilization under standard conditions known to those of skill in the art provides the desired formulation. In some embodiments, the resulting solution can be apportioned into vials for lyophilization. Each vial can contain a single dosage or multiple dosages of the compound. The lyophilized powder can be stored under appropriate conditions, such as at about 4° C. to room temperature.

Reconstitution of this lyophilized powder with water for injection provides a formulation for use in parenteral administration. For reconstitution, the lyophilized powder is added to sterile water or other suitable carrier. The precise amount depends upon the selected compound. Such amount can be empirically determined.

The antibodies or antigen-binding portions thereof, the bispecific molecule, or the immunoconjugate described herein and other compositions provided herein can also be formulated to be targeted to a particular tissue, receptor, or other area of the body of the subject to be treated. Many such targeting methods are well known to those of skill in the art. All such targeting methods are contemplated herein for use in the instant compositions. For non-limiting examples of targeting methods, see, e.g., U.S. Pat. Nos. 6,316,652, 6,274,552, 6,271,359, 6,253,872, 6,139,865, 6,131,570, 6,120,751, 6,071,495, 6,060,082, 6,048,736, 6,039,975, 6,004,534, 5,985,307, 5,972,366, 5,900,252, 5,840,674, 5,759,542 and 5,709,874. In a specific embodiment, the anti-FAM19A5 antibody or antigen-binding portion thereof described herein can be used treat a fibrosis and/or a disease or condition associated with fibrosis.

The compositions to be used for in vivo administration can be sterile. This is readily accomplished by filtration through, e.g., sterile filtration membranes.

IX. Kits

Provided herein are kits comprising one or more antibodies described herein, or antigen-binding portions thereof, bispecific molecules, or immunoconjugates thereof. In some embodiments, provided herein is a pharmaceutical pack or kit comprising one or more containers filled with one or more of the ingredients of the pharmaceutical compositions described herein, such as one or more antibodies provided herein or an antigen-binding portion thereof, optional an instructing for use. In some embodiments, the kits contain a pharmaceutical composition described herein and any prophylactic or therapeutic agent, such as those described herein.

EXAMPLES

The following experimental methods and details are referenced in the Examples that follow.

Example 1 Expression and Purification of Human FAM19A5 Protein

Recombinant human FAM19A5 protein was produced and purified and the purified protein was used in an antibody screening assay based on binding affinity analysis. First, LPS-hT plasmid containing the FAM19A5 gene was transformed into bacteria and protein over-expression was induced. Once produced, the FAM19A5 protein was purified using an Ni-NTA affinity chromatography (Qiagen, Valencia, Calif., USA). Using gradually higher concentration of imidazole, we removed the His-tagged FAM19A5 protein from the Ni-column. The protein expression in the solution is measured using Coomassie Brilliant Blue R-250 Dye. Taking only the FAM19A5 immidazole containing solution, we concentrated the FAM19A5 protein using PBS. When the concentration was complete, both the purity and concentration of the FAM19A5 protein were measured using a Western Blot assay. The concentrated protein was subsequently used to screen for FAM19A5-specific antibodies.

Example 2 Production of Antibody Libraries FAM19A5

The FAM19A5 protein was used as antigen for immunization of a chicken. 50 μg of the synthetic peptide KLH conjugate was mixed in 750 μl phosphate buffered saline (PBS) and incubated at 37° C. for 30 minutes. Afterwards, the toxin is removed in a 2% squalene endotoxin MPL (monophosphorylate lipid A species) and mycobacteria (mycobacteria) of the cell wall components of TDW and CWS containing a water-in-oil emulsion adjuvant (RIBI+MPL+TDM+CWS adjuvant, Sigma, St. Louis, Mo., USA) in emulsified, which was then subcutaneously injected into three chickens. The chickens were immunized for a total of three times, approximately 2-3 weeks apart between immunization. The titer of the antibodies obtained from the immunized chickens was measured via immune blotting using lysates of HEK293T cells which overexpressed the FAM19A5 protein. Sera from chickens that received the three immunizations were used as primary antibody. The secondary antibody used was anti-chicken IgG(Y) polyclonal antibody conjugated to HRP (Horseradish peroxidase) (Rabbit anti-chicken IgG (Y)-HRP, Millipore corporation, Billeria, Mass., USA).

Single-chain variable fragment (scFv) library was prepared from immunized chicken Using™ reagent (Invitrogen, Carlsbad, Calif. USA), we extracted RNAs from the spleen, bone marrow, and synovial sac of the immunized chickens described above. Oligo-dT primers and SUPERSCRIPT™ III First-Strand Synthesis System (Invitrogen) were used to synthesize the first strand cDNA. For the cDNA obtained from the immune system of chickens, Expand High Fidelity PCR System (Roche Molecular Systems, Ind., USA) was used to produce a single chain variable region library. In each reaction, 1 μL of cDNA, 60 pmol of each primer, 10 μL of 10× reaction buffer solution, 8 μL of 2.5 mM dNTP (Promega, Madison, Wis., USA), and 0.5 μL of Taq DNA polymerase were mixed with water. The final volume was 100 μL PCR reaction was performed using the following conditions: 30 cycles of (i) 15 seconds at 94° C. (ii)30 seconds at 56° C., and (iii) 90 seconds at 72° C., followed by a final extension for 10 minutes at 72° C. The PCR products comprising a fragment having a length of about 350 bp were loaded onto a 1.5% agarose gel and after electrophoresis, QIAGEN Gel II Extraction Kit (QIAGEN, Valencia, Calif., USA) was used to purify the nucleotide fragment. The purified PCR product was quantified by reading at OD 260 nm. (1 unit OD=50 μg/ml).

Two VH and VL first products from the second PCR were connected randomly by the overlap extension PCR (Overlap extension PCR). Each PCR reaction was mixed with 100 ng of the purified VL and VH products, 60 pmol of each primer, 10 μL 10× reaction buffer, 8 μL of 2.5 mM dNTP, 0.5 μL of Taq DNA polymerase, and water in a final volume of 100 μL of. PCR was performed under the following conditions: 25 cycles of (i) 15 seconds at 94° C., (ii) 30 seconds at 56° C., and (iii) 2 minutes at 72° C., followed by final extension for 10 minutes at 72° C. The PCR products comprising a single chain variable region fragment having a length of about 700 bp were loaded onto a 1.5% agarose gel and after electrophoresis, QIAGEN II Gel Extraction Kit (QIAGEN) was used to purify the nucleotide fragment. The purified PCR product was quantified by reading at OD 260 nm. (1 unit OD=50/ml).

The scFv fragment of the PCR product and vector pComb3X-SS (The Scripps Research Institute, Calif., USA) were digested with a Sfi I restriction enzyme. 10 μg of the purified overlapping PCT product was mixed with 360 units of Sif I, (μg DNA per 16 units, Roche Molecular Systems, Pleasanton, Calif., USA), 20 μL of a 10× reaction buffer, and water to the final volume with 200 μL. 20 μg of the pComb3X-SS vector was mixed with 120 units of Sfi I (μg DNA per 6 units), 20 μL of a 10× reaction buffer solution, and water to the final volume to 200 μL. The mixture was digested at 50° C. for 8 hours. Afterwards, the digested product comprising the scFv fragment (about 700 bp) and the vector (about 3400 bp) was loaded onto a 1% agarose gel and purified using a Gel Extraction Kit II QIAGEN (QIAGEN, Valencia, Calif., USA). 1400 ng of the Sfi I-restricted pComb3X vector and 700 ng of the digested scFv fragments were mixed with 5× a ligase buffer, 10 μL of T4 DNA ligase (Invitrogen, Carlsbad, Calif., USA), and water to a final volume of 200 μL. The mixture was incubated at 16° C. for 16 hours to perform the ligation.

After precipitation with ethanol, the DNA pellet was dissolved in 15 μL of water.

To produce a library, the ligation sample was transformed into E. coli strain ER2738 (New England Biolabs Inc, Hitchin, Hertfordshine, SG4 OTY, England, UK) via electroporation using the vibrator gene (Gene pulser: Bio-Rad Laboratories, Hercules, Calif., USA). Cells were mixed in a 5 ml Super Broth (SB) medium and incubated while stirring at 250 rpm for one hour at 37° C. Then, 3 μL of 100 mg/mL kanamycin was added to 10 mL of SB medium. To determine the library size, 0.1 μL and 10 μL of the culture sample were smeared onto Luria Broth (LB) agar plates containing 50 μg/mL of kanamycin. After stirring for 1 hour, 4.5 μL of 100 mg/mL kanamycin was added to the LB culture and further stirred for an additional 1 hour. Then, 2 ml of the VCM13 helper phage in water (>10¹¹ cfu/ml) was added to the LB medium, along with pre-heated LB (183 mL) containing 92.5 μL of 100 mg/mL kanamycin. This mixture was stirred at 250 rpm at 37° C. for an additional 2 hours. Next, 280 μL (50 mg/mL) of kanamycin was added to the culture and stirred overnight at 37° C. The next day, the bacteria pellet was centrifuged using a high-speed centrifuge (Beckman, JA-10 rotor) at 3,000 g, 4° C. Afterwards, the bacterial pellet was used to extract phagemid DNA, while the supernatant was transferred to sterile centrifuge bottles. Next 8 grams of polyethylene glycol-8000 (PEG-8000, Sigma) and 6 grams of sodium chloride was added (NaCl, Merck) to the supernatant, and then kept for 30 minutes in ice. Afterwards, the supernatant was centrifuged 15 minutes at 15,000 g, 4° C. The supernatant was then discarded, and the phage pellet Tris containing 1% BSA—reproduction was suspended in buffered saline (TBS).

Example 3 Library Panning (Bio-Panning) on an Immobilized Antigen

Bio-panning was performed using magnetic beads (Dynabeads M-270 Epoxy, Invitrogen). At room temperature, approximately 1×10⁷ beads were coated with 5 μg of recombinant FAM19A5 protein by stirring, while rotating, the beads and the protein together for 20 hours at room temperature. Once the coating was done, the beads were washed 4 times with phosphate buffered saline (PBS) and blocked for one hour in PBS containing 3% BSA at room temperature. Then, the coated beads were cultured for two hours at room temperature with Phage-displayed scFv described above. To remove any phage that was not bound to the antigen coated beads, the beads were washed with 0.05% Tween20/PBS. Then the bound phages were eluted with 50 μL of 0.1M glycine/hydrogen chloride (0.1M Glycine-HCl, pH 2.2) and neutralized with 3 μL of 2M Tris with hydrogen chloride (tris-HCl, pH 9.1). This phage-containing supernatants were used to infect E. coli ER2738 cells and VCSM13 helper phage was used to amplify and rescue overnight. Also the input (input) and production (output) by phage titers from the phage-infected cultures were determined by blotting the phage-infected cultures on LB agar plates containing 50 μg/ml of kanamycin. The next day, PEG-8000 and NaCl were used to precipitate phages, which were used subsequently for bio-panning. Bio-panning was performed up to a total of five different times by repeating the above process. With each amplification, the phages were screened and selected for high affinity to the FAM19A5 protein.

Example 4 Selection of Clone by Phage ELISA

To analyze the clones selected from the bio-panning, we randomly selected individual clones from the phase-displayed scFv and confirmed using ELISA that the clones bind to the FAM19A5 recombinant protein. The FAM19A5 recombinant protein was diluted in 0.1M NaHCO₃ buffer, and 100 ng/well of the protein was used to coat 96-well microtiter plates at 4° C. for 16 hours. Next day, the plates were blocked with 3% BSA/PBS at 37° C. for 1 hour. Then, the phage supernatant was mixed with 6% BSA/PBS and was cultured for 2 hours at 37° C. The plates containing the supernatant were then washed with 0.05% Tween20/PBS. The HRP-conjugated M13 antibody (a-M13-HRP, Pierce Chemical Co, Rockford, Ill., USA) was diluted to 1/5000. 50 μL of the diluted antibody was added to the plates and incubated for 1 hour at 37° C. After the incubation and washing, the plates were added with 0.05M citrate buffer solution, 1 μg/ml of 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS, Amresco, Solon, Ohio, USA), and 0.1% H₂O₂ for color development. The absorbance for each well was measured at 405 nm.

24 clones that bind to the FAM19A5 recombinant protein and show high absorbance were analyzed. From the 24 clones, we obtained 13 scFv clones having unique sequences. After further selecting the clones, we obtained clone 1-65 having the highest affinity.

Example 5 Production of Anti-FAM19A5-IgG2/4 Antibody

Anti-FAM19A5 scFv was subcloned into a mammalian expression vector In the FAM19A5 scFv gene sequence, a human Cκ gene was connected to the light chain variable domain, and human immunoglobulin isotype IgG2/4 of CH1, CH2, and CH3 genes were connected to the heavy chain variable region. The antibody having each light chain and each heavy chain was synthesized by adding restriction sites (Genscript, USA). The synthesized gene was inserted into the mammalian cell expression vector having a modified restriction site to facilitate cloning. First, the light chain gene was inserted into the vector using Hind III and Xba I (New England Biolabs, UK) restriction enzymes and then adding the heavy chain gene to the vector by using NheI and BamHI (New England Biolabs, UK) restriction enzymes.

In order to express and purify an anti-FAM19A5-IgG2/4 antibody, we used a mammalian cell transfection and overexpression injection system. We mixed 2 μg/ml of the mammalian expression vector with 4 μg of polyethyleneimine (PEI, Polysciences, Warrington, Pa., USA) in 150 mM sodium chloride (NaCl, Merck) corresponding to 1/10 of the cell culture volume. The mixture was allowed to stand for 15 minutes at room temperature. The mixture was added to HEK293F cells (2×10⁶ cells/ml, Invitrogen), which were then incubated in the FREESTYLE™ 293 expression culture medium containing 100U/ml of penicillin and streptomycin (Invitrogen) at 7% CO₂ and 37° C. and in a stirring condition of 135 rpm for six days. To purify the expressed anti-FAM19A5 IgG2/4 antibodies from the cell culture supernatant, we used Protein A bead (RepliGen, Waltham, Mass., USA) affinity gel chromatography. The protein A chromatography was run on 4˜12% Bis-Tris gradient gel electrophoresis. The size and yield of the protein was confirmed by the Coomassie Brilliant Blue staining.

Example 6 Serum Analysis in Liver Fibrosis

In order to assess the level of FAM19A5 protein in liver fibrosis, a rat model of liver fibrosis (i.e., bile duct ligation (BLD)-induced hepatic fibrosis Sprague-Dawley (SD) rat model) was used. See Kountouras et al., Br J Exp Path 65:305-311 (1984). Briefly, the animals were anesthetized with ketamine and xylazine. A 1.5-cm midline incision was made and the common bile duct was located and double ligated with 3-0 silk ligatures. Then, at 21 days post hepatic fibrosis induction, whole blood was collected from the animals and the serum was separated from the whole blood.

The level of FAM19A5 protein in the sera was measured using the FAM19A5 sandwich ELISA assay. A 96-well ELISA plate was coated overnight with 1 μg/mL of 1-65 human IgG1 anti-FAM19A5 antibody in a 100 μL volume. The plate was then washed with PBS and subsequently blocked with 1% BSA in PBS for 1 hour at room temperature. Next, the plate was again washed with PBS and approximately 100 μL of the standard and the sample were dispensed into the appropriate wells. The plate was then incubated at room temperature for 2 hours. Afterwards, the plate was washed with 0.05% PBS-Tween 20 (i.e., the wash buffer) and approximately 100 μL of the detection antibody (horse radish peroxidase (HRP) conjugated goat a-rabbit IgG antibody (Santa Cruz, Cat # SC-2030), diluted 1:5000 in 1% BSA in PBS) was added to the wells. The plate was incubated at room temperature for an additional 1 hour. After additional washes with the wash buffer, approximately 100 μL of the O-Phenylenediamine Dihydrochloride (OPD) substrate was added to each of the wells, and the plate was allowed to develop at room temperature. After about 10 minutes, approximately 100 μL of 1N H2SO4 (sulfuric acid) was added to the wells to stop the reaction. The absorbance was immediately measured at a wavelength of 492 nM using a 96-well MicroPlate Reader (Molecular Device, Versa Max).

As shown in FIG. 1, the level of FAM19A5 protein was more than 3 times higher in the serum of the BDL-induced hepatic fibrosis SD rats (“disease model”) as compared to that of the normal (i.e., non-BDL-induced) rats.

Example 7 Serum Analysis in Lung Fibrosis

In order to assess whether the level of FAM19A5 protein also increased in lung fibrosis, idiopathic pulmonary fibrosis was induced in 7-week-old male SD rats by administering 3 mg/kg of bleomycin via intratracheal injection. At 24 days post bleomycin administration, whole blood was collected from the animals and the serum was separated from the whole blood. The level of FAM19A5 protein in the sera was measured using the FAM19A5 sandwich ELISA assay as shown in Example 6 above. As shown in FIG. 2, the level of FAM19A5 protein was more than 1.5 times higher in the serum of the pulmonary fibrosis induced SD rats (“disease model”) as compared to that of the normal (i.e., no idiopathic pulmonary fibrosis) rats.

Example 8 Serum Analysis of Human Liver Fibrosis Patients

AST and/or ALT levels can increase in the serum upon hepatocyte damage and such increases have often been relied on to suggest liver damage. See Gowda et al., Pan Afr Med J 3:17 (2009); Giannini et al., Arch Intern Med 163:218-224 (2003). However, when the damage is severe (e.g., cirrhosis), the AST and ALT levels can appear normal. Therefore, to assess whether FAM19A5 expression can be a better indicator of liver damage, the level of FAM19A5 protein was measured in the serum of human patients with confirmed cirrhosis using the FAM19A5 sandwich ELISA assay.

The 2-13 anti-FAM19A5 human IgG1 antibody was reconstituted at a concentration of 1 μg/μL in 50 mM carbonate buffer (Bio-World, Cat. C2070-9.6, Lot. C70-9.616Z11C). The anti-FAM19A5 antibody was then diluted at a ratio of 1:1000 in PBS and subsequently used to coat a 96-well ELISA plate overnight. The next day, the plate was washed with PBS and subsequently blocked with 1% BSA in PBS at room temperature for about 1 hour. Afterwards, the plate was again washed with PBS and approximately 100 μL of the standard and samples were dispensed into the appropriate wells. The plate was incubated at room temperature for 2 hours. Afterwards, the plate was washed with 0.05% PBS-Tween 20 (i.e., the wash buffer). Next, the 3-2 anti-FAM19A5 mouse IgG2a antibody reconstituted at a concentration of 1 μg/μL was diluted at a ratio of 1:2000 in 1% BSA in PBS. Approximately 100 μL of this diluted antibody was added to each of the wells and the plate was allowed to incubate for an additional 2 hours at room temperature. After additional washes with the wash buffer, approximately 100 of the horse radish peroxidase (HRP) conjugated donkey α-mouse IgG antibody (Jackson Lab, Cat. 715-035-151, Lot. 122401) (diluted 1:5000 in 1% BSA in PBS) was added to the wells. The plate was subsequently incubated for 1 hour at room temperature. After the incubation, the plate was washed with the wash buffer and approximately 100 μL of the 1-STEP™ Ultra TMB-ELISA substrate solution (Pierce, Cat. 34028, Lot. QJ20436540) was added to each of the wells. After a 10-minute incubation, approximately 100 μL of 1N H2SO4 (sulfuric acid) was added to the wells to stop the reaction. The absorbance was immediately measured at a wavelength of 450 nM using a 96-well MicroPlate Reader (Molecular Device, Versa Max).

As shown in FIG. 3, patients with cirrhosis had FAM19A5 protein levels that were approximately 2-6 fold greater than those observed in the sera of normal healthy individuals. Such data is in agreement with the animal studies described above and indicates that the serum concentration of FAM19A5 protein can be an ideal diagnostic marker for cirrhosis.

Example 9 Analysis of Effect on Myocardial Infarction

Ischemic cell death that occurs during a myocardial infarction leads to a reparative response in which the damaged tissue is replaced with a fibrotic scar. This is followed by remodeling of the surrounding tissue (e.g., left ventricular wall thinning and chamber dilatation) and eventually leading to impaired cardiac function. See Talman et al., Cell Tissue Res 365(3):563-581 (2016); Firth et al., Cardiovasc Drugs Ther 4:1363-1374 (1990). To assess the effect of anti-FAM19A5 antibody on myocardial infarction, a mouse ischemic reperfusion model was used. Briefly, Balb/cAnNCrljOri mice (6 weeks old, male) (Orient Bio Inc., Seoul, South Korea) were purchased and housed in specific pathogen-free (SPF) conditions for approximately 1 week. Afterwards, the mice were deeply anesthetized with Zoletil 50 (VIRBAC, France) and zylazine (Rompun®, Bayer AG, Germany). Once anesthetized, open thoracotomy was performed on the mice to expose the coronary artery, and myocardial infarction was induced by ligating the artery using a 7-0 suture and a PE20 tube. The ischemic condition was maintained for 40 minutes, at which point, the blood was reperfused by removing the PE20 tube. Beginning at day 3 post myocardial infarction induction, the anti-FAM19A5 antibodies (1-65, 3-2, or 1-28 antibodies) were administered to the mice via intravenous injection at weekly intervals for a total of three injections. Naïve (i.e., healthy) and NHI mice were used as controls.

On day 21 post myocardial infarction induction, the mice were sacrificed and their hearts harvested. The heart tissues were fixed in a 10% formalin solution. Then, the fixed heart tissues were sliced transversely with a thickness of 2 mm around the apex and placed in paraffin blocks, which were further sliced into 5 μm sections and mounted onto glass tissue slides for analysis. Hematoxylin and eosin (H & E) staining was performed on the heart tissue samples to assess the effect of each anti-FAM19A5 antibody (i.e., 1-65, 3-2, and 1-28 antibodies) on myocardial infarction-associated tissue remodeling.

As expected, the heart tissues from the NHI control group exhibited significant dilatation of the left ventricle and thinning of the left ventricular wall. See FIG. 4 (“NHI”). In contrast, the heart tissues from mice that received the anti-FAM19A5 antibodies resembled heart tissues from naïve (“healthy”) animals (i.e., decreased left ventricular dilatation and preservation of the left ventricular wall tissues).

To help quantify this effect, Masson's trichrome, which stains for collagen, was performed on the heart tissue sections. As noted earlier, collagen is a major component of the extracellular matrix (ECM) and therefore, Masson's Trichrome staining of increased collagen accumulation in a tissue sample can be an accurate indicator of fibrosis. The stained slides were photographed using an optical microscope (Olympus BX53, Japan) and the ratio of fibrous area to the total left ventricular area was also calculated using an image analyzer.

As shown in FIG. 5A, mice that received the anti-FAM19A5 antibodies had significantly less accumulation of collagen compared to the NHI control group. In the anti-FAM19A5 antibody treated groups, approximately 10-15% of the total left ventricular area was made up of fibrous tissue. See FIG. 5B. In contrast, in mice from the NHI control group, the fibrous area made up approximately 20% of the total left ventricular area. Among the different FAM19A5 antibodies, the 1-65 antibody appeared to have the greatest effect.

Collectively, the above results demonstrate that the administration of FAM19A5 antibodies soon after myocardial infarction can greatly improve tissue remodeling and fibrosis formation.

Example 10 Anti-Fibrosis Effect of Anti-FAM19A5 Antibody in DMN (Dimethylnitrosamine)-Mediated Fibrosis Model

To assess the anti-fibrosis effect of anti-FAM19A5 antibody, a liver fibrosis animal model was used. Briefly, dimethylnitrosamine (DMN) (diluted in saline at a concentration of 10 mg/ml/kg) was administered to rats via intraperitoneal injection for 3 consecutive days (once a day) for 4 consecutive weeks. Starting at week 5 post initial DMN administration, the animals received either the control human IgG antibody or an anti-FAM19A5 antibody once a week for 2 weeks. See FIG. 6A. Then, a week after the last antibody administration (i.e., week 7 post initial DMN administration), the animals were sacrificed, bled, and liver tissue harvested. The obtained liver tissues were fixed in 10% buffered neutral formalin. Then, the tissues were embedded in paraffin and sliced tissue sections (˜4-5 μm thick) were obtained.

The progression of liver fibrosis can be confirmed by the accumulation of extracellular matrix, which can be confirmed by Sirius red staining, which specially stained for collagen, a typical component of extracellular matrix. Therefore, to assess the degree of fibrosis progression in the animals, sliced tissue sections were stained with Sirius Red staining and photographed at a magnification of 100× using a microscope. Then, the relative frequency of Sirius Red-positive cells within the stained liver tissue section was determined using an Image analyzer (Image Pro Plus 7.0, MediaCybernetics, USA).

As shown in FIGS. 6B and 6C, the liver of DMN-treated animals that received the anti-FAM19A5 antibody (G3) had significantly reduced area with Sirius red-positive staining, compared to animals that received the control (human IgG) antibody (G2). This result suggested that anti-FAM19A5 administration can inhibit DMN-induced collagen production in liver fibrosis tissue.

To confirm the above observation, immunohistochemical staining for type I collagen was also performed on the sliced tissue sections. Briefly, sliced tissue sections were stained for type I collagen and photographed at a magnification of 100× using a microscope. Then, the percentage of area with positive type I collagen expression relative to the total stained tissue section was determined using an Image analyzer (Image Pro Plus 7.0, MediaCybernetics, USA). As shown in FIGS. 6D and 6E, compared to animals that received the control antibody, animals that received the anti-FAM19A5 antibody had significantly reduced type I collagen staining in their liver, confirming the results from the Sirius Red staining.

As further confirmation, immunohistochemistry was also used to quantitate transforming growth factor beta (TGF-β) production, which is an important factor in the development and progression of liver fibrosis. Briefly, sliced tissue sections were stained for TGF-β and photographed at a magnification of 100× using a microscope. Then, the percentage of area with positive TGF-β expression relative to the total stained tissue section was determined using an Image analyzer (Image Pro Plus 7.0, MediaCybernetics, USA). As shown in FIGS. 7A and 7B, TGF-β production was significantly reduced in the liver of DMN-treated animals that received the anti-FAM19A5 antibody, compared to those animals treated with the control antibody.

Collectively, the above data indicated that, in an animal model of liver fibrosis induced by DMN, anti-FAM19A5 antibody can inhibit the production of both collagen and TGF-β, demonstrating the anti-fibrosis effect of the antibody.

It is to be appreciated that the Detailed Description section including the Summary and Abstract sections is intended to be used to interpret the claims. The Summary and Abstract sections can set forth one or more but not all exemplary embodiments of the present disclosure as contemplated by the inventor(s), and thus, are not intended to limit the present disclosure and the appended claims in any way.

The present disclosure has been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.

The foregoing description of the specific embodiments will so fully reveal the general nature of the disclosure that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance.

The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

All publications, patents, patent applications, internet sites, and accession numbers/database sequences (including both polynucleotide and polypeptide sequences) cited herein are hereby incorporated by reference in their entirety for all purposes to the same extent as if each individual publication, patent, patent application, internet site, or accession number/database sequence were specifically and individually indicated to be so incorporated by reference.

This PCT application claims the priority benefit of U.S. Provisional Application Nos. 62/525,633, filed Jun. 27, 2017, and 62/582,886, filed Nov. 7, 2017, both of which are incorporated herein by reference in their entireties. 

What is claimed is:
 1. An antagonist against a family with sequence similarity 19, member A5 (FAM19A5) protein (“FAM19A5 antagonist”) for treating a fibrosis of a tissue in a subject in need thereof.
 2. The FAM19A5 antagonist for use of claim 1, wherein the fibrosis is selected from the group consisting of a hepatic fibrosis, pulmonary fibrosis, renal fibrosis, myelofibrosis, pancreatic fibrosis, skin fibrosis, cardiac fibrosis, arterial fibrosis, arthrofibrosis, breast fibrosis, muscle fibrosis, retroperitoneal Fibrosis, thyroid fibrosis, lymph node fibrosis, bladder fibrosis, systemic fibrosis, and pleural fibrosis.
 3. The FAM19A5 antagonist for use of claim 1 or 2, wherein the FAM19A5 antagonist decreases accumulation of an extracellular matrix protein (e.g., collagen) within the tissue.
 4. The FAM19A5 antagonist for use of any one of claims 1 to 3, wherein the FAM19A5 antagonist is an antibody, or an antigen-binding portion thereof, that specifically binds to the FAM19A5 protein (“anti-FAM19A5 antibody”).
 5. The FAM19A5 antagonist for use of claim 4, wherein the anti-FAM19A5 antibody is a chimeric antibody, a humanized antibody, or a human antibody.
 6. The FAM19A5 antagonist for use of claim 4 or 5, wherein the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 11, 12, and 13, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 23, 24, and 25, respectively.
 7. The FAM19A5 antagonist for use of claim 4 or 5, wherein the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 14, 15, and 16, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 26, 27, and 28, respectively.
 8. The FAM19A5 antagonist for use of claim 4 or 5, wherein the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 17, 18, and 19, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 29, 30, and 31, respectively.
 9. The FAM19A5 antagonist for use of claim 4 or 5, wherein the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 20, 21, and 22, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 32, 33, and 34, respectively.
 10. A method of in vitro diagnosing a fibrosis or a fibrosis-associated disease comprising contacting an FAM19A5 antagonist with a biological sample of the subject and measuring a FAM19A5 protein level or a FAM19A5 mRNA level in the sample.
 11. The method of claim 10, wherein the FAM19A5 antagonist is an anti-FAM19A5 antibody.
 12. The method of claim 11, wherein the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 11, 12, and 13, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 23, 24, and 25, respectively.
 13. The method of claim 11, wherein the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 14, 15, and 16, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 26, 27, and 28, respectively.
 14. The method of claim 11, wherein the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 17, 18, and 19, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 29, 30, and 31, respectively.
 15. The method of claim 11, wherein the anti-FAM19A5 antibody comprises a heavy chain CDR1, CDR2, and CDR3, and a light chain CDR1, CDR2, and CDR3, wherein the heavy chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 20, 21, and 22, respectively, and the light chain CDR1, CDR2, and CDR3 comprises SEQ ID NOs: 32, 33, and 34, respectively. 